I keep having the issue as well except I also can't replace the world, cancel the realm or reset the world either. This game has been nothing but bugs, and I can't even play my own realm, I'm paying freaking money for this and still can't play? What the heck Mojang. Earlier I had a bug with nether portals and now this! Please fix this!
I have had the same issue on my worlds, most notably on my realm
The issue seems to be fixed now