Different parenting styles

Okay long story short. I was with my daughter father for 4.5 years, I finally got out when she was 2.5. (DV). That was back in 2018.

He still continued to eff with us until I grew strong enough to know better.

Moving forward a couple of years, I met my current partner in 2020 and we started dating in July 20, have been to cheer since. In the last 3 months. We seem to be butting heads constantly, only in regards yo my daughter whom is now 6. He has a son who is 1.5.

I feel like he just attacks her constantly. He just always seems to get up her. She has witnessed DV. She also has sensory issues and since she was little we have been seeing a paediatrician every 6 months as others is something there that I need help with. She is just full on. She needs melatonin to fall asleep. And of course she is a butthole to my partner as her father while has eff all to do with her manipulates her into thinking he js the bees knees. I dunno what I’m wanting from this. I just need to vent and need some advice. Do I leave my current partner or what.