I've been having this problem for months, now. When using melee and unarmed weapons in third person, I almost always wind up watching the same animation. It differs for weapon each weapon type: for bladed weapons you run up and cut their throat, for two-handed melee, despite whether its bladed or blunt you jam it in their eye, unarmed almost always winds up either driving your knee into their face or a superman punch to the mouth. For some reason blunt one-handed weapons use this as well.
First person animations seem to be completely untouched by this and work fine.
I have tried removing all of my mods manually, nuking my directory, checking for loose files and removing them. I've tried reverting everything to its original state and still this persists. I'm at a loss as to what else to try, so some help will be much appreciated.
I should also note that I am using the steam version and I did use Vortex for my mod manager.