I have the same problem. I cannot access any of my manual saves. Additionally, I cannot cast spells. The one difference is that I am on a PS4 console, not a PS5
I cannot access any manual saves post update on my PS4, also I cannot use any spell casting (it occasionally lets me cast igni, but it is random). As a result the game is unplayable until it is patched. Im on level 29, I dont want to start over.