Same problem. Started after i reinstalled the game. Now the most recently played character is at the bottom of the list instead of at the top. So annoying!
Edit:
It turns out the order can be fixed by entering a game with every character on the list, and moving an item to or from the stash.
After doing this for all my characters, the list is now again most recently played on top.
I think it might be due to the item being moved forcing an update to the local character file, but i’m not sure.