Rooms and scenes that you want to use in the new V3 app should be created in the new V3 app.
The name change is not showing up in the new app is definitely annoying, but my understanding is that they will eventually show up, it’s just that it can take a day or so. 
As far as the other issues, there is an existing thread that discusses the specific differences between the two apps. You’re definitely not seeing things, there are some very real differences.