@NovotnyJ Jan what’s the reason behind making the GroupBox bigger then the size of the CW?
Something you can try is to use % to size your GroupBox width=“100%” height=“100%” which automatically sizes the Groupbox to the size of the CW.
I just imported and used your CW in my project and didn’t have any issue (using AS 6.1.100) One recommendation I would make is setting the left position to 0 since otherwise your GroupBox right side will be cut off.
Also in case you are not aware there is a really nice solution allowing you the “import/export” CW into standalone content making it possible to use the visual editor.