MDL-80403 communication_matrix: Fixed convert power levels to array

The curent patch revealed a bug inside set_matrix_power_levels
where returned user power levels contained an array of objects.
Other methods were failing and giving incorrect responses
as they were expecting arrays.

communication/provider/matrix/classes/communication_feature.php

@@ -598,6 +598,12 @@ class communication_feature implements
         $currentpowerlevels = $this->get_current_powerlevel_data();
         $currentuserpowerlevels = (array) $currentpowerlevels->users ?? [];
 
+        // Ensure each user entry is an array.
+        $currentuserpowerlevels = array_map(
+            fn ($user) => (array) $user,
+            $currentuserpowerlevels,
+        );
+
         // Get all the current users who need to be in the room.
         $userlist = $this->processor->get_all_userids_for_instance();
 
@@ -656,7 +662,10 @@ class communication_feature implements
     private function get_users_with_custom_power_level(array $users): array {
         return array_filter(
             $users,
-            function ($level): bool {
+            function ($user): bool {
+                // Isolate the level value.
+                $level = array_values($user);
+                $level = reset($level);
                 switch ($level) {
                     case matrix_constants::POWER_LEVEL_DEFAULT:
                     case matrix_constants::POWER_LEVEL_MOODLE_SITE_ADMIN: