Issues with my Realm completely

My son resubscribed to realms after changing his name, so it created a different realm, and it won’t allow us to upload his world into his new realm. We have tried to change world slots and reset the worlds, but it continues to load continually or gets an error. Now I would be ok with just starting a whole new world, but it won’t open the world and can’t get the server to temporarily close to resolve some kind of connection issue. I have tried uploading and resetting the world slots multiple times on Xbox X series and also a PC but nothing works and I think the Realm is deadlocked and need to be reset from the other end.