The "Mark text changes" in the Editor preferences (Options -> Text editor -> Display) is not working properly: when you start Creator it acts as it's enabled even if it's not. In order to disable marking text changes you have to enable it, click OK to close the options disalog, then open the editor preferences again, deselect "Mark text changes", and then click "OK" again to close the options dialog, and you have to do this every time you start Creator.
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This works fine in 3.2.2.