Global users are not visible on User Directory (sub)wiki

Steps to reproduce:

1. Create a (sub)wiki with an user who has rights to do this (I created a wiki with an user who was on a group)
   1. User scope - both users (local and global)
   2. Open for anyone to join the (sub)wiki
2. The created wiki can be accessed
3. Login on Main wiki with a global user
4. Go to "Wiki Index"
5. Join the new created wiki
6. Go to that new wiki
7. Go to "User Directory"
8. Instead of local users, you are not able to see the global users who joined the wiki