problem with logging out in mimecraft

Hello.
I have the problem that I can no longer log out of MinecraftPe. I can log in and out of the Xbox app as normal, but Minecraft just doesn't work. I uninstalled the Minecraft game and reinstalled it again to see if this worked. unfortunately it didn't work.
I can also no longer access the marketplace, my skins and the servers. I've tried everything that was written on the forums about minecraft problems, but unfortunately they didn't help.
I hope you can help me.
(I'm sorry for my English, but I'm from Germany)