I’ve been trying the new responsive engine and everything seemed intuitive until yesterday. RGs seem to be the hardest thing for me. Right now I have a RG with a row layout, with a number of row- and column layout groups within it.
I’ve had this a couple of times in the early versions of the new engine. Sometimes it would go away with a refresh, but I’m guessing you’ve tried this before.
Some random ideas I would try:
Try removing some of the width or height constraints and see if one of the fixes. My hunch is that there’s one of those percentages is conflicting with another one. Specially if you set a group at 100% and it has margins on it. Or even borders. Maybe there’s a funky sharp edge there somewhere.