Hi Andrew,
Good day and thank you for your question. I reproduced it on my end using the following endpoint below on Graph Explorer and did not receive any error:
- GET https://graph.microsoft.com/v1.0/users/******@domain.com/joinedTeams
- GET https://graph.microsoft.com/v1.0/users/{user-ID}/joinedTeams
Can I please know the following:
- Does it only happen on specific user?
- Does it work when using the user principal name?