For some reason every time I try to join my friend's realm, it always says "You need to authenticate to Microsoft services" and it has NEVER done that before. I'm on MCPE too. I'm logged in my Xbox and Microsoft account and in my settings for Microsoft it says I'm able to play multiplayer. I tried deleting Xbox and Minecraft and reinstalled it still didn't work!

Edit: I joined the realm but as I joined it, there was nothing in my inventory and I didn’t spawn where I usually spawned.