Player 2 character won't load on Switch

I own a realm to play with my sons on Switch. We had some split screen issues for a week or two in the spring. While it had been working otherwise through winter and spring, we returned to minecraft for some stormy days this summer, and found that while we can split screen again, it won't load my son's characters on player 2. It loads a guest character, with no experience or inventory. Whoever launches the game as player 1 gets their proper character, and player 2 gets a guest character. This is on a realms account on switch. New bug noticed this summer.