Lost Save file on Xbox One S

Xbox one S
Roughly 2 years ago i played Generation Zero for many hours, almost 100% the game. After maybe a month of playing(was a long time ago cant remember how long it was/ how many hours, probably a lot), but then one day i load up my xbox, start up generation zero and find that my character was lost. At the time i had the Alpine unrest and FNIX rising dlc and had just the night prior i think bought the US weapons pack (i also had all of the currently available free vanity packs). I frequently played solo as well as playing with a freind, probably a 50/50 split (this was always the same 1 vfreind(this freind did not have any paid dlc, doubt this affects though as they were previously able to join my game when i had dlc)).