Using the OnParentNodeChange, automatic focusing of the editor is expected and it is the way this method is designed to act.
This method is used to fix the editor when moved trough the DOM. It attaches all needed events with te core functionality and repaints the editor according the wrapper's size. Using it on an invisible editor is incorrect.
Due to that I suggest redesigning the behavior by implementing a logic that calls the OnParentNodeChanged only when the editor is shown.
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