There is a container having a grid layout and containing group boxes with column spans.
If you take a look at “Group 1” you will see that the border of the group box is cut off on the right side.
I played around with many things like setting experimental padding, margin to any widget that makes sense in the broadest sense, but all tries have been unsuccessful.
My workaround is to add a dummy widget to the last column + 1 (so this column is a dummy as well). That´s working for me and is not too bad.
J But this should just be a workaround and not the final solution.