This specific issue only happens with one of my friends. His gamertag is "jobetyk" and he is an Android user. (He speaks spanish). He can invite me but I can't join any of his worlds. The error message is "You must authenticate to Xbox Live" even though I am logged in. He told me that he has never had anyone his worlds. I don't know how to reproduce the issue other than you friending him and telling him to invite you.

jobetyk's device: Sony Xperia M2 Lollipop Android version: 5.1.1