I set up my groupboxes under macOS, and they and their content (checkboxes, radio buttons, etc) look as I want them to. Under Windows, it seems that the top 8 pixels or so of the groupbox is not used (or perhaps is used for the caption). Either way this resulted in the layout looking bad as the groupboxes were not tall enough.
A simple fix seemed to be that in the Open event I move Top up by 8px and increase Height by 8px. This restores the right size but controls contained within the groupbox get dragged upwards by 8px, so I have to add Open events for each control that add 8px to Height. And then the groupbox and its content look good.
Simple enough, but tedious if one has many groupboxes, so I'm wondering if there is a tidier or better way to do this. I develop under macOS and then, for Windows, test in W7 and W10 VMs, which are good enough for testing but a bit slow for development.
Any clues appreciated.