>>311759368
Try out other models and find one that has acceptable behavior, then look at how it's weighted. If you want to get more advanced, you can correct some bad behaviors with weighting with "twist bones" and unity constraints, but I don't know if it'll help your exact issue
https://vrcat.club/threads/tutorial-guide-twist-bones-what-are-they-and-how-do-you-use-them.3622/