How frustrating! I've experienced the same problem in the past. Hopefully, this is just a temporary behavioral problem! She can't verbalize that she's upset about the loss of one companion and upset about the changes so this is her way of showing how upset/mad she is.
Many advise in multi-cat...
I used to have a membership here, but can't seem to remember my old log in.
These forums are so wonderfully helpful and I'm happy to be back!
Diana L Benoit