Whenever I invite a friend to my realm it says their security issues prevent them from joining. Their security options are all wide open, as are mine, for the purposes of combating this issue. No matter the settings, nobody can join my realm.
REALMS-756
Can't Invite Friends
Resolved
Cannot Reproduce
0
Your friends need to be of certain age or have parental consent to join Realms. In order to do that some settings on Xbox website need to be changed. You can see a picture below.
Go to your Xbox account, go to Profile - Privacy & Online Safety - XboxOne/Win10 Online Safety and make sure you can join clubs and connect to multiplayer games.