Steam Cloud issues after Win 11 24H2 update

[i c wiener]

After the Win 11 24H2 update (which was pushed to my PC on 18 Oct), I started having frequent issues syncing to Steam Cloud. There were no such problems before.

The odd thing is that these problems are completely unpredictable - some days they occur very often and some days not at all, or they randomly occur across different instances on the same day. I have not managed to pinpoint anything I've done in particular to trigger them, as they also occur with a variety of games.

The other odd thing is it only affects the auto cloud sync after I quit the game. Syncing when I exit Steam or when I start another instance of the game is completely unaffected and always works. There are also absolutely no other problems with Steam services, including downloading updates, visiting the store, etc.

I've tried various solutions, eg verifying the integrity of games' caches, repairing library, even changing my DNS servers, but no solution has been lasting. None of my games are even close to the cloud save capacity, either.

Steam support is not able to help so far. The only significant change to my system that led to this issue was Win 11 24H2. Any ideas that won't involve me reinstalling Windows? Because that would be a real pain.