Yes +1 on this. In many ways I love the new responsive engine, so when I redesigned all my pages using it I made some extra tweaks. Now after reading this thread it looks like I’m going to have to revert to the old responsive engine for this particular page that has drag and drop, which will now look inconsistent with my newly updated front end!
Hopefully they fix this soon because it’s super annoying.
Also, I assume this is related, now when I drag a ‘drag group’, the content inside it disappears. Not sure if this is a glitch, or maybe it’s just the way I’ve tried to hack my way through it. With the old responsive engine it was easier to nest groups within groups, but now with flexbox it’s a bit trickier.