Microsoft account losing connection on restart - logging back in results in game/console crashes

Since the latest update, all microsoft accounts associated to users on the two switch Systems in my household continuously lose connection when starting Minecraft.

Attempting to log back in causes the game, or the switch itself to crash, either the home menu freezes or the game gets stuck in a loop on the home screen, or with no menu visible, but the background nether scenery continues to rotate.

The game had become virtually unplayable.