Ex-Echos M had a similar struggle when she was trying to adapt to her new (not new now) therapist. Although I think the dynamics with her old T were unhealthy in different ways than yours, she had a hard time with the meh feelings of the new therapist despite the fact that he had all the qualities that made him a good therapist (stable, secure, insightful, etc.). For a long while, it seemed, the new one just lacked the emotional charge of the old one, but she went with her gut to stay with the new one and it has really paid off. If she's around, maybe she can explain it better.

Sometimes, issues with therapists that mirror family dynamics cannot be worked out with that very therapist. If yours is that reactive, it's like you are forever locked in the same dysfunctional bond as what you have with your mother. I'd say something differently if she had managed to steady herself better, but it sounds like she's still bouncing around emotionally?