I'm sorry OP. I agree with the PP . . . she is individuating and this could partly just be normal teen behavior.

Also, she knows that your love is secure. Her father's is not. So if she focuses on him while he's love bombing her, it's because it's a precious and unpredictable resource. He won't be able to sustain the false enthusiasm forever, and eventually she will remember who really loves her and is always there for her.

In the meantime, focus on supports for yourself.

I would offer that if you and your STBX were getting along beautifully, your 14 year old might still be cold to you and appear to be pulling away. This is typical adolescent behavior. My guess is that this behavior is not as bad as you’re perceiving it to be, but that it is happening on some level. Stay calm and loving. Be there for her. Don’t be clingy. Set boundaries and expect pushback.
Hang in there.

This will be difficult to combat. It is essentially mental warfare.

Parental Alienation is an insidious form of child abuse which can have life-long negative effects on both the child and their "targeted" parent's relationship.

I would suggest you contact a family therapist who specializes in PA. This is far too complex and critical to go without professional help.

Good luck.

STBX has been verbally and emotionally abusive and since we have starting the divorce process, he’s been trying to alienate DD (14). It’s been months and she basically is getting colder and colder to me. I always thought I’ll never give up on her, I love her so much, but it’s just getting worse. Trust me, I don’t push it, just try to be available and be nice, kind and stable. He live bombs her, but never used to care at all. Never did anything with her, couldn’t care less and now he’s all over her…