Friend can not join my realm

Since the new update to MCPE v1.1.0.0 my friend can not connect to my realm since it doesn't appear in his friends tab. While joining seams to work with other iOS devices, he is unable with his android phone. I kicked him off the realm and invited him again. He receives the invites but the realm still doesn't pop up. I can see that he is online so his account should be fine