Switch minecraft wont let user join xbox world

When me and my friend try and play minecraft her switch doesnt let her join my world, I am playing on the xbox one where the world was created, she is playing on her switch and when i send an invite it gives her an error being "Unable to connect please restart your client" "P2P/SIG:no_session(Expired auth from discovery)" she has restarted her device, signed in and out, checked her internet connection (It was fine) and I have left the world, reopened it, sent her invites, and made it where she could join if she wanted to without an invite and it still gives her this error