diff --git a/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp b/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
index 0678b2b99c..d5bef1d2f9 100644
--- a/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
+++ b/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
@@ -691,10 +691,30 @@ void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSche
                       mirrorY ? "y" : "" );
     }
 
-    // The symbol unit is always set to the first instance regardless of the current sheet
+    // The symbol unit is always set to the ordianal instance regardless of the current sheet
     // instance to prevent file churn.
-    int unit = ( aSymbol->GetInstances().size() == 0 ) ? aSymbol->GetUnit()
-                                                       : aSymbol->GetInstances()[0].m_Unit;
+    SCH_SYMBOL_INSTANCE ordinalInstance;
+
+    ordinalInstance.m_Reference = aSymbol->GetPrefix();
+
+    const SCH_SCREEN* parentScreen = static_cast<const SCH_SCREEN*>( aSymbol->GetParent() );
+
+    wxASSERT( parentScreen );
+
+    if( parentScreen && m_schematic )
+    {
+        std::optional<SCH_SHEET_PATH> ordinalPath =
+                m_schematic->Hierarchy().GetOrdinalPath( parentScreen );
+
+        wxASSERT( ordinalPath );
+
+        if( ordinalPath )
+            aSymbol->GetInstance( ordinalInstance, ordinalPath->Path() );
+        else if( aSymbol->GetInstances().size() )
+            ordinalInstance = aSymbol->GetInstances()[0];
+    }
+
+    int unit = ordinalInstance.m_Unit;
 
     if( aForClipboard && aRelativePath )
     {
@@ -732,7 +752,7 @@ void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSche
             // sheet instance to prevent file churn.
             if( id == REFERENCE_FIELD )
             {
-                field.SetText( aSymbol->GetInstances()[0].m_Reference );
+                field.SetText( ordinalInstance.m_Reference );
             }
             else if( id == VALUE_FIELD )
             {
diff --git a/eeschema/schematic.cpp b/eeschema/schematic.cpp
index be84355169..8ba07e4eac 100644
--- a/eeschema/schematic.cpp
+++ b/eeschema/schematic.cpp
@@ -221,9 +221,7 @@ SCH_SHEET_LIST SCHEMATIC::Hierarchy() const
 
 void SCHEMATIC::RefreshHierarchy()
 {
-    wxLogDebug( wxS( "Refreshing schematic heirarchy." ) );
-
-    m_hierarchy = SCH_SHEET_LIST( m_rootSheet );
+    m_hierarchy = BuildSheetListSortedByPageNumbers();
 }
 
 
diff --git a/eeschema/schematic.h b/eeschema/schematic.h
index 31a7b7bf96..d101a1edb2 100644
--- a/eeschema/schematic.h
+++ b/eeschema/schematic.h
@@ -96,7 +96,11 @@ public:
 
     SCH_SHEET_LIST BuildSheetListSortedByPageNumbers() const override
     {
-        return SCH_SHEET_LIST( m_rootSheet );
+        SCH_SHEET_LIST hierarchy( m_rootSheet );
+
+        hierarchy.SortByPageNumbers();
+
+        return hierarchy;
     }
 
     SCH_SHEET_LIST BuildUnorderedSheetList() const
diff --git a/eeschema/widgets/hierarchy_pane.cpp b/eeschema/widgets/hierarchy_pane.cpp
index f2ee8eeb8a..d4e3d5d8c6 100644
--- a/eeschema/widgets/hierarchy_pane.cpp
+++ b/eeschema/widgets/hierarchy_pane.cpp
@@ -417,11 +417,11 @@ void HIERARCHY_PANE::onRightClick( wxTreeItemId aItem )
 
         if( dlg.ShowModal() == wxID_OK && dlg.GetValue() != itemData->m_SheetPath.GetPageNumber() )
         {
+            SCH_COMMIT commit( m_frame );
             SCH_SHEET_PATH parentPath = itemData->m_SheetPath;
             parentPath.pop_back();
 
-            m_frame->SaveCopyInUndoList( parentPath.LastScreen(), itemData->m_SheetPath.Last(),
-                                         UNDO_REDO::CHANGED, false );
+            commit.Modify( itemData->m_SheetPath.Last(), parentPath.LastScreen() );
 
             itemData->m_SheetPath.SetPageNumber( dlg.GetValue() );
 
@@ -431,7 +431,7 @@ void HIERARCHY_PANE::onRightClick( wxTreeItemId aItem )
                 m_frame->OnPageSettingsChange();
             }
 
-            m_frame->OnModify();
+            commit.Push( wxS( "Change sheet page number." ) );
 
             UpdateLabelsHierarchyTree();
         }