Invitation envelope not appearing cannot join realm

A friend is trying to invite me to join his realm. I get a notice which pops up on screen that I have been invited, however the invitation envelope usually seen under the friends tab does not appear. He tried giving me the invitation code, but after entering it, I receive a message that reads I must have the owners permission before joining the realm. I have two realms myself and I am a member of another friends realm. These I have no problem joining. Please let me know if there are any steps we can take to get me in his realm, thank you!