Yep, I’m stuck at 11 characters now, and any new one that I create disappears after restarting the game. This happens even if I create several characters, all of them will dissapear.
Funnily enough, a few months ago I was stuck in the same situation with 10 characters (New characters won't save after closing game (Nintendo Switch)) and one day a new sorc saved properly and I didn’t lose it, but now it’s happening again. I reinstalled the game (Switch) but that didn’t solve it.