Ah! This is entirely because Vrchat does not like dynamicbones anymore, they've transitioned to Physbones. In unity, go to the vrchat dropdown and in there is an option to convert dynamicbones to physbones. Do that and it should fix things
ok I'll take a look back at the unitypackage and redo it to hopefully fix the issue once and for all for everyone. I have work tomorrow but monday night I have off to check stuff hopefully