My account gamertag changed/account changed

 I cannot play with any of my friends on Minecraft after the update a few days ago. 
cannot load world. I have tried everything to fix issue! 
-Logged out and back in

-signed out of Microsoft account back in

-deleted Minecraft redownloaded

-Entered Xbox to allow multiplayer (those were both ahead allowed) 

-No parental code or age restrictions

-Strong Internet

-Cleared Cache

-Uninstalled packs/add ons

-made new world 

-tried a new world on friends world (wouldn’t connect) 

-Deleted internet settings & saved address reconnected

 NONE worked! It is like my account is an Xbox one instead of my Nintendo switch one and I cannot play with anyone unless I go on a server and that works! 
how can I join a server but am not allowed to play multiplayer with my Nintendo switch friends?