[realcopacetic]

I can confirm getting the same behaviour.

Not sure what the cause is but it only happens when the grouplist is center aligned. If you left align the grouplist then it doesn't happen. Seems to be some sort of delay between the control becoming visible and the recalculation of the alignment

Thanks for confirming! I'll go back to left aligned and it should be fine, thanks 

There must be a difference in how labels and buttons are rendered as it doesn't happen with labels. Is there scope for this to be looked at in the actual rendering engine? Not sure if this would be considered a bug or not