I’ve played 5 games so far, and every one, at some point, developed saves that could not be loaded. I could see and load older saves but my most recent always disappear from the load page. All saves are present in the correct folder, they are simply not available within the game. I am running some mods but all are current, and none conflict with each other.
edit: if I load an old save, then do a quicksave, the missing saves reappear and are available to load.