After a lot of back and forth with Dream Support, the problem was solved for me.
I was logged in with a secondary account and not with the main account.
The option "Rename room" is missing for the secondary account under:
"Map management for multiple rooms" -》Room separation

I have only found how to rename the map, but I do not have the Rename function under:
Select icon with pen, then "Map management for multiple rooms" -》Room separation -》Select room

Yes, select the pencil icon, then select "Map management for multiple rooms" -》Room partitioning -》Room and select Rename.

There is an icon in the top right-hand corner of the app where you can edit the map. There you can change the names under "Rename".