Model's head and face tearing apart during animation

[cookie jar]

I'm making some custom model, kinda frankensteined it out of different models and a head done by me. I successfully rigged it, however i'm having this problem with the head and face tearing apart during animation. I guess it's probably a problem with weights, but no matter what weightpainting i tried it didn't solve the problem. Any tips to fix this? Link to the model: https://drive.google.com/file/d/1AUA0FFzLrVIMQ8-BjVjJMBemqplPv5wa/view?usp=drive_link

[The Punisher]

Seems like a weight mismatch. To put it on Layman's terms, all "interconnecting" vertices must match the exact same weight(s).

[cookie jar]

4 hours ago, The Punisher said:

Seems like a weight mismatch. To put it on Layman's terms, all "interconnecting" vertices must match the exact same weight(s).

Yeah i changed some cranium and cervical weights and it seems to be better now