Xbox series X game save gone after updates

Hi,
I lost 100’s of hours of game play after the history of updates , two characters , everything. When I tried to play on my XBSX , I had to start a new game. So I started a new game , which had all the updates and DID NOT like the new characters look , what happened? I uninstalled the game and reinstalled from my disk on (Xbox one , all game saves gone too) and got back the normal characters. So, I’m afraid if I update , I’m going to lose my character and / or games saves again. Will the updates overwrite or delete my present game saves? If so, I wont bother ever updating , I’ll just play the game again as is.

Thanks.