[MCPE-59011] Crash on startup (or going online) using login with Microsoft-account

Child account on Microsoft family.
No problem to play and access files etc..
Updated child account on account.xbox to be able to accept friends (to more easily play LAN-games with his brother).
Not able to start Minecraft. Crashes on startup. Can start Minecraft offline, but as soon the device goes on line, the game crashes.
If using non-Microsoft account, the game starts and is fully functioning