Can't add a Member to a Group

I have several members of my team that I’m trying to add to our Group. For a couple of them, I can find them and add them. For a couple of them, I can’t find them when I search on their name or email alias. They’re in Outlook, but I can’t find them in a search. Any idea of what I can do to fix this?


This question seems unrelated to the Gitlab CI section.

So pls change it to match the right category and explain some more:

  • Selfhosted / instance
  • Authentication method (LDAP?)