Nosencrantz and Butterscotch remain in my office/bedroom. They don’t want to leave it.
They are also unimpressed when I let the other cats in.

The only other cat they accept is Cheddar. They will even cuddle with him. They have no desire to associate with any of the other cats, and most of the other cats don’t like seeing them, either.
We’ve never had cats so completely at odds with other cats like this, and certainly never had any that keep themselves to only one room. They actually seem quite content in their private domain – until other cats show up.
I don’t know how to fix this.
At least they get along with each other and Cheddar, but I’d really like to not have a litter box in my room!
The Re-Farmer