Ctrl+z/+y doesn’t work after previewing on a new server. The buttons don’t work either/are greyed out.
Hello. I believe this will be down to the fact that the transition from the editor to the new server and then back to the editor will lose the undo/re-do stack.
I’m just checking with the team now to see if this can be resolved and will get back to you 
Yes as I suspected. The operations stored in the undo/re-do stack are lost on server transition, which is why you can’t perform those actions when returning from a new preview server