Same thing for me. I was on week 21. I'd tidied up my save files after getting loads of bugs and crashes, so I looked online and found the stuff about only keeping 1 save file.
Xbox gamepass version has been really unstable. I want to like this game but it's so frustrating to be this buggy.
Now, after trying to tidy up saves, there is nothing at all in the game, continue and load are greyed out.
In the Xbox system I can see 3 save files at 256.4 mb but nothing in game, so there's data, that the game just doesn't want to read.
Such a disappointment, as the idea of the game is fun, but it just doesn't work.