I have a 4 year old female (Opal) who’s 4 year old male partner passed away in December 2022. She immediately became depressed so I attempted to bond her with another male in January 2023. I attempted bonding every single day for multiple hours a day but ultimately this pairing did not work out because the male kept hurting her (ripped her ear, pulled out all her whiskers, broke skin with fur pulling).
In April I took her on some bunny dates and she did well with a 2 year old female (Winnie). They were interested in each other and Opal even licked her on the head once. When we got home we realized Winnie had not been socialized very much so she was extremely reactive, growling and lunging anytime anything got close to her. This made bonding quite rocky at the beginning but we were able to overcome that with some car rides and bonding sessions everyday. Things seemed to be progressing well and I had very high hopes for the bond working out, there was cuddling, mutual grooming, sharing a litterbox, sharing toys, and eating together. So about two weeks ago I decided to do the 48 hour test and they passed except for one single nip from Opal over a hidey house which I read would be okay. When I moved them in together in Opals room I cleaned everything thoroughly with vinegar, even the walls, and got all new stuff for their shared space. They were still cuddling and happy in their permanent home for about 6 hours, then Opal started chasing Winnie and nipping her as well. It hasn’t been violent but it was enough that I had to separate them and now we’ve gone back to dates in neutral space that last 4-8 hours and they still cuddle, mutually groom, share food, but the nipping and chasing from Opal will not stop and Winnie is trying to run away but she seems anxious.
I thought maybe it was a territory issue so I packed them up and went to my moms house to have a brand new completely neutral space where I attempted to marathon bond them but the behavior is exactly the same. It’s almost like they’re in love for 5 minutes, then Opal just decides to start nipping and chasing Winnie seconds after they were just cuddling and grooming each other.
I really thought they were bonded based on my experience bonding my last pair but this random aggression in throwing me for a loop because based on all their positive behavior together most would consider them bonded. I’m starting to think maybe they are bonded but Opal is just a bully because it’s been weeks and there’s just no progress.

Has anyone else experienced this?? I just don’t know what to do from here.