diff --git a/.upgradenotes/MDL-82913-2025011510021468.yml b/.upgradenotes/MDL-82913-2025011510021468.yml
new file mode 100644
index 00000000000..8062c6e4562
--- /dev/null
+++ b/.upgradenotes/MDL-82913-2025011510021468.yml
@@ -0,0 +1,8 @@
+issueNumber: MDL-82913
+notes:
+  core_reportbuilder:
+    - message: >-
+        When the `select` filter contains upto two options only then the
+        operator field is removed, switching to a simpler value selection field
+        only (this may affect your Behat scenarios)
+      type: changed
diff --git a/.upgradenotes/MDL-84213-2025011422342259.yml b/.upgradenotes/MDL-84213-2025011422342259.yml
new file mode 100644
index 00000000000..2b6c79e4b7b
--- /dev/null
+++ b/.upgradenotes/MDL-84213-2025011422342259.yml
@@ -0,0 +1,7 @@
+issueNumber: MDL-84213
+notes:
+  core_reportbuilder:
+    - message: >-
+        The `select` filter type is now stricter in it's filtering, in that it
+        will now discard values that aren't present in available filter options
+      type: changed
diff --git a/admin/roles/tests/reportbuilder/datasource/roles_test.php b/admin/roles/tests/reportbuilder/datasource/roles_test.php
index d327e4c9762..06422006d59 100644
--- a/admin/roles/tests/reportbuilder/datasource/roles_test.php
+++ b/admin/roles/tests/reportbuilder/datasource/roles_test.php
@@ -149,7 +149,7 @@ final class roles_test extends core_reportbuilder_testcase {
             ], true],
             'Filter role name (no match)' => ['role:name', [
                 'role:name_operator' => select::EQUAL_TO,
-                'role:name_value' => -1,
+                'role:name_value' => $DB->get_field('role', 'id', ['shortname' => 'teacher']),
             ], false],
             'Filter role archetype' => ['role:archetype', [
                 'role:archetype_operator' => select::EQUAL_TO,
diff --git a/cohort/tests/reportbuilder/datasource/cohorts_test.php b/cohort/tests/reportbuilder/datasource/cohorts_test.php
index d3a8e4e8b17..b9c202b91cb 100644
--- a/cohort/tests/reportbuilder/datasource/cohorts_test.php
+++ b/cohort/tests/reportbuilder/datasource/cohorts_test.php
@@ -149,9 +149,9 @@ final class cohorts_test extends core_reportbuilder_testcase {
                 'cohort:context_operator' => select::EQUAL_TO,
                 'cohort:context_value' => system::instance()->id,
             ], true],
-            'Filter content (no match)' => ['cohort:context', [
-                'cohort:context_operator' => select::EQUAL_TO,
-                'cohort:context_value' => -1,
+            'Filter context (no match)' => ['cohort:context', [
+                'cohort:context_operator' => select::NOT_EQUAL_TO,
+                'cohort:context_value' => system::instance()->id,
             ], false],
             'Filter name' => ['cohort:name', [
                 'cohort:name_operator' => text::IS_EQUAL_TO,
diff --git a/competency/tests/reportbuilder/datasource/competencies_test.php b/competency/tests/reportbuilder/datasource/competencies_test.php
index ccd3aa9d9f0..0adb9a56636 100644
--- a/competency/tests/reportbuilder/datasource/competencies_test.php
+++ b/competency/tests/reportbuilder/datasource/competencies_test.php
@@ -187,8 +187,8 @@ final class competencies_test extends core_reportbuilder_testcase {
                 'framework:scale_value' => '<SCALEID>',
             ], true],
             'Framework scale (no match)' => ['framework:scale', [
-                'framework:scale_operator' => select::EQUAL_TO,
-                'framework:scale_value' => -1,
+                'framework:scale_operator' => select::NOT_EQUAL_TO,
+                'framework:scale_value' => '<SCALEID>',
             ], false],
             'Framework visible' => ['framework:visible', [
                 'framework:visible_operator' => boolean_select::CHECKED,
diff --git a/course/tests/reportbuilder/datasource/categories_test.php b/course/tests/reportbuilder/datasource/categories_test.php
index 2d57dc84699..996b07283b4 100644
--- a/course/tests/reportbuilder/datasource/categories_test.php
+++ b/course/tests/reportbuilder/datasource/categories_test.php
@@ -194,7 +194,7 @@ final class categories_test extends core_reportbuilder_testcase {
             ], true],
             'Filter role (no match)' => ['role:name', [
                 'role:name_operator' => select::EQUAL_TO,
-                'role:name_value' => -1,
+                'role:name_value' => $DB->get_field('role', 'id', ['shortname' => 'teacher']),
             ], false],
 
             // User.
diff --git a/course/tests/reportbuilder/datasource/courses_test.php b/course/tests/reportbuilder/datasource/courses_test.php
index 1a6ea203313..96ec7d00461 100644
--- a/course/tests/reportbuilder/datasource/courses_test.php
+++ b/course/tests/reportbuilder/datasource/courses_test.php
@@ -82,6 +82,7 @@ final class courses_test extends core_reportbuilder_testcase {
             'category' => $category->id,
             'fullname' => 'Cats',
             'summary' => 'Course description',
+            'lang' => 'en',
             'theme' => 'boost',
             'tags' => ['Horses'],
         ]);
@@ -161,8 +162,8 @@ final class courses_test extends core_reportbuilder_testcase {
         $this->assertEquals('Yes', $coursevisible);
         $this->assertEquals('No groups', $coursegroupmode);
         $this->assertEquals('No', $coursegroupmodeforce);
-        $this->assertEmpty($courselang);
-        $this->assertEmpty($coursecalendar);
+        $this->assertEquals('English ‎(en)‎', $courselang);
+        $this->assertEquals('Do not force', $coursecalendar);
         $this->assertEquals('Boost', $coursetheme);
         $this->assertEquals('No', $coursecompletion);
         $this->assertEmpty($coursedownload);
@@ -273,7 +274,7 @@ final class courses_test extends core_reportbuilder_testcase {
             ], true],
             'Filter course format (no match)' => ['course:format', [
                 'course:format_operator' => select::EQUAL_TO,
-                'course:format_value' => 'weekly',
+                'course:format_value' => 'weeks',
             ], false],
             'Filter course startdate' => ['course:startdate', [
                 'course:startdate_operator' => date::DATE_RANGE,
@@ -315,7 +316,7 @@ final class courses_test extends core_reportbuilder_testcase {
             ], true],
             'Filter course lang (no match)' => ['course:lang', [
                 'course:lang_operator' => select::EQUAL_TO,
-                'course:lang_value' => 'de',
+                'course:lang_value' => '',
             ], false],
             'Filter course calendartype' => ['course:calendartype', [
                 'course:calendartype_operator' => select::EQUAL_TO,
@@ -323,7 +324,7 @@ final class courses_test extends core_reportbuilder_testcase {
             ], true],
             'Filter course calendartype (no match)' => ['course:calendartype', [
                 'course:calendartype_operator' => select::EQUAL_TO,
-                'course:calendartype_value' => 'hijri',
+                'course:calendartype_value' => '',
             ], false],
             'Filter course theme' => ['course:theme', [
                 'course:theme_operator' => select::EQUAL_TO,
diff --git a/reportbuilder/classes/local/entities/course.php b/reportbuilder/classes/local/entities/course.php
index a21ea0a51f4..df658c44c50 100644
--- a/reportbuilder/classes/local/entities/course.php
+++ b/reportbuilder/classes/local/entities/course.php
@@ -409,7 +409,7 @@ class course extends base {
      * @return array
      */
     public static function get_options_for_theme(): array {
-        return array_map(
+        return ['' => get_string('forceno')] + array_map(
             fn(theme_config $theme) => $theme->get_theme_name(),
             get_list_of_themes(),
         );
@@ -421,7 +421,7 @@ class course extends base {
      * @return array
      */
     public static function get_options_for_lang(): array {
-        return get_string_manager()->get_list_of_translations();
+        return ['' => get_string('forceno')] + get_string_manager()->get_list_of_translations();
     }
 
     /**
@@ -430,7 +430,7 @@ class course extends base {
      * @return array
      */
     public static function get_options_for_calendartype(): array {
-        return \core_calendar\type_factory::get_list_of_calendar_types();
+        return ['' => get_string('forceno')] + \core_calendar\type_factory::get_list_of_calendar_types();
     }
 
     /**
@@ -452,7 +452,7 @@ class course extends base {
 
         // If the column has corresponding filter, determine the value from its options.
         $options = $this->get_options_for($fieldname);
-        if ($options !== null && array_key_exists($value, $options)) {
+        if ($options !== null && $value !== null && array_key_exists($value, $options)) {
             return $options[$value];
         }
 
diff --git a/reportbuilder/classes/local/entities/user.php b/reportbuilder/classes/local/entities/user.php
index 7e35f4ea5a0..5db1401830f 100644
--- a/reportbuilder/classes/local/entities/user.php
+++ b/reportbuilder/classes/local/entities/user.php
@@ -364,7 +364,7 @@ class user extends base {
 
         // If the column has corresponding filter, determine the value from its options.
         $options = $this->get_options_for($fieldname);
-        if ($options !== null && array_key_exists($value, $options)) {
+        if ($options !== null && $value !== null && array_key_exists($value, $options)) {
             return $options[$value];
         }
 
diff --git a/reportbuilder/classes/local/filters/select.php b/reportbuilder/classes/local/filters/select.php
index 5ecb3f0aa88..c42d4be60fd 100644
--- a/reportbuilder/classes/local/filters/select.php
+++ b/reportbuilder/classes/local/filters/select.php
@@ -44,6 +44,9 @@ class select extends base {
     /** @var int Not equal to */
     public const NOT_EQUAL_TO = 2;
 
+    /** @var int Value to indicate "Any value" for the simplified filter options  */
+    private const OPTION_ANY_VALUE = -124567;
+
     /**
      * Returns an array of comparison operators
      *
@@ -65,7 +68,13 @@ class select extends base {
      * @return array
      */
     protected function get_select_options(): array {
-        return (array) $this->filter->get_options();
+        static $options = [];
+
+        if (!array_key_exists($this->name, $options)) {
+            $options[$this->name] = (array) $this->filter->get_options();
+        }
+
+        return $options[$this->name];
     }
 
     /**
@@ -91,7 +100,7 @@ class select extends base {
                 $element,
                 "{$this->name}_value",
                 get_string('filterfieldvalue', 'core_reportbuilder', $this->get_header()),
-                ['' => $operators[self::ANY_VALUE]] + $options,
+                [self::OPTION_ANY_VALUE => $operators[self::ANY_VALUE]] + $options,
             )->setHiddenLabel(true);
         } else {
             $elements = [];
@@ -129,13 +138,19 @@ class select extends base {
         $name = database::generate_param_name();
 
         $operator = (int) ($values["{$this->name}_operator"] ?? self::ANY_VALUE);
-        $value = $values["{$this->name}_value"] ?? '';
+        $value = (string) ($values["{$this->name}_value"] ?? self::OPTION_ANY_VALUE);
 
         $fieldsql = $this->filter->get_field_sql();
         $params = $this->filter->get_field_params();
 
+        // Get available options, if multidimensional then flatten the array.
+        $options = $this->get_select_options();
+        if (count($options) !== count($options, COUNT_RECURSIVE)) {
+            $options = array_merge(...array_values($options));
+        }
+
         // Validate filter form values.
-        if ($value === '') {
+        if ($operator === self::ANY_VALUE || !array_key_exists($value, $options)) {
             return ['', []];
         }
 
diff --git a/reportbuilder/tests/local/filters/select_test.php b/reportbuilder/tests/local/filters/select_test.php
index 6bbbc6b9a42..ed34079b1f7 100644
--- a/reportbuilder/tests/local/filters/select_test.php
+++ b/reportbuilder/tests/local/filters/select_test.php
@@ -43,8 +43,12 @@ final class select_test extends advanced_testcase {
             [select::ANY_VALUE, null, true],
             [select::EQUAL_TO, 'starwars', true],
             [select::EQUAL_TO, 'mandalorian', false],
+            [select::EQUAL_TO, '', false],
+            [select::EQUAL_TO, 'invalid', true],
             [select::NOT_EQUAL_TO, 'starwars', false],
             [select::NOT_EQUAL_TO, 'mandalorian', true],
+            [select::NOT_EQUAL_TO, '', true],
+            [select::NOT_EQUAL_TO, 'invalid', true],
         ];
     }
 
@@ -64,11 +68,11 @@ final class select_test extends advanced_testcase {
 
         $course1 = $this->getDataGenerator()->create_course([
             'fullname' => "May the course be with you",
-            'shortname' => 'starwars',
+            'idnumber' => 'starwars',
         ]);
         $course2 = $this->getDataGenerator()->create_course([
             'fullname' => "This is the course",
-            'shortname' => 'mandalorian',
+            'idnumber' => '',
         ]);
 
         $filter = (new filter(
@@ -76,10 +80,11 @@ final class select_test extends advanced_testcase {
             'test',
             new lang_string('course'),
             'testentity',
-            'shortname'
+            'idnumber'
         ))->set_options([
-            $course1->shortname => $course1->fullname,
-            $course2->shortname => $course2->fullname,
+            $course1->idnumber => $course1->fullname,
+            $course2->idnumber => $course2->fullname,
+            'mandalorian' => 'This is not the course you are looking for',
         ]);
 
         // Create instance of our filter, passing given operator.
diff --git a/reportbuilder/tests/local/helpers/custom_fields_test.php b/reportbuilder/tests/local/helpers/custom_fields_test.php
index 1be2aee68ec..c5c5258603d 100644
--- a/reportbuilder/tests/local/helpers/custom_fields_test.php
+++ b/reportbuilder/tests/local/helpers/custom_fields_test.php
@@ -70,7 +70,7 @@ final class custom_fields_test extends core_reportbuilder_testcase {
 
         $generator->create_field(
             ['categoryid' => $category->get('id'), 'type' => 'select', 'name' => 'Select', 'shortname' => 'select',
-                'configdata' => ['options' => "Cat\nDog", 'defaultvalue' => 'Cat']]);
+                'configdata' => ['options' => "Cat\nDog\nFish", 'defaultvalue' => 'Cat']]);
 
         $generator->create_field(
             ['categoryid' => $category->get('id'), 'type' => 'number', 'name' => 'Number', 'shortname' => 'number',
diff --git a/reportbuilder/tests/local/helpers/user_profile_fields_test.php b/reportbuilder/tests/local/helpers/user_profile_fields_test.php
index 2060320e2e5..8986bea2b87 100644
--- a/reportbuilder/tests/local/helpers/user_profile_fields_test.php
+++ b/reportbuilder/tests/local/helpers/user_profile_fields_test.php
@@ -50,7 +50,8 @@ final class user_profile_fields_test extends core_reportbuilder_testcase {
                 'defaultdata' => 0, 'visible' => PROFILE_VISIBLE_NONE]);
 
         $this->getDataGenerator()->create_custom_profile_field([
-            'shortname' => 'menu', 'name' => 'Menu field', 'datatype' => 'menu', 'param1' => "Cat\nDog", 'defaultdata' => 'Cat']);
+            'shortname' => 'menu', 'name' => 'Menu field', 'datatype' => 'menu', 'param1' => "Cat\nDog\nFish",
+                'defaultdata' => 'Cat']);
 
         $this->getDataGenerator()->create_custom_profile_field([
             'shortname' => 'Social', 'name' => 'msn', 'datatype' => 'social', 'param1' => 'msn']);
diff --git a/user/tests/reportbuilder/datasource/users_test.php b/user/tests/reportbuilder/datasource/users_test.php
index 6a9cd0ec053..0c2a38820c2 100644
--- a/user/tests/reportbuilder/datasource/users_test.php
+++ b/user/tests/reportbuilder/datasource/users_test.php
@@ -386,8 +386,8 @@ final class users_test extends core_reportbuilder_testcase {
                 'user:lang_value' => 'en',
             ], true],
             'Filter lang (no match)' => ['user:lang', [
-                'user:lang_operator' => select::EQUAL_TO,
-                'user:lang_value' => 'de',
+                'user:lang_operator' => select::NOT_EQUAL_TO,
+                'user:lang_value' => 'en',
             ], false],
             'Filter timezone' => ['user:timezone', [
                 'user:timezone_operator' => select::EQUAL_TO,