reinstantiate properly tasks previews

--this code helps the previewsmodel to
reinstantiate when changing from single
instance preview to another single one

plasmoid/package/contents/ui/task/TaskItem.qml

@@ -1066,6 +1066,10 @@ MouseArea{
         windowsPreviewDlg.visualParent = previewsVisualParent;
 
         toolTipDelegate.parentTask = taskItem;
+
+        //! WORKAROUND, in order for toolTipDelegate to re-instantiate the previews model when
+        //! previews are changing from single instance preview to another single instance
+        toolTipDelegate.rootIndex = undefined;
         toolTipDelegate.rootIndex = tasksModel.makeModelIndex(itemIndex, -1);
 
         toolTipDelegate.hideCloseButtons = hideClose;