So I just recruited the Dwemer artifact woman and the man at the bear cave, but when I go back to Fort Dawnguard Vori and the other guard woman are hostile with me and everyone else at the fort. Does anyone know why this would happen? And yes I tried reloading.

I dont know the cause, but try waiting 3 days and then going back there.

this happened to me, reloaded an auto save from when i was in whiterun, worked for me.