Try to force a repaint on selection changed.

src/modules/partition/gui/PartitionLabelsView.cpp

@@ -494,6 +494,17 @@ PartitionLabelsView::setCustomNewRootLabel( const QString& text )
 }
 
 
+void
+PartitionLabelsView::setSelectionModel( QItemSelectionModel* selectionModel )
+{
+    connect( selectionModel, &QItemSelectionModel::selectionChanged,
+             this, [=]
+    {
+        viewport()->repaint();
+    } );
+}
+
+
 QModelIndex
 PartitionLabelsView::moveCursor( CursorAction cursorAction, Qt::KeyboardModifiers modifiers )
 {

src/modules/partition/gui/PartitionLabelsView.h

@@ -49,6 +49,8 @@ public:
 
     void setCustomNewRootLabel( const QString& text );
 
+    void setSelectionModel( QItemSelectionModel* selectionModel ) override;
+
 protected:
     // QAbstractItemView API
     QRegion visualRegionForSelection( const QItemSelection& selection ) const override;