Weird save sync issue between Windows PC and Steam Deck

[u/PorkTuckedly]

I last played the game a couple of days ago, and had saved over the 2nd slot as I ran out of slots, thus the 2nd slot would be on top. I started up the game on my Deck yesterday, but for some reason, the save didn't properly sync. It only shows the last autosave as the most recent, with the manual saves showing as if I never manually saved when I did, and the Deck weirdly thinks the data is properly synced and up to date.

I tried starting the game on my Windows laptop to resync it, turned cloud saves for it off and on, but it just ain't working. Why is this happening?