Microsoft Graph not returning shared calendars for Tenant Admin user

Question

Hello

I was trying Graph Explorer to check what calendars can I read using this endpoint :

https://graph.microsoft.com/v1.0/users/<user-id>/calendars

And saw that not all users are able to read the shared calendars when the user-id is the tenant admins.

For instance, the admin shares his personal calendar with User A and User B. Only User A sees a valid response back, User B sees the below error.

{
    "error": {
        "code": "ErrorItemNotFound",
        "message": "The specified object was not found in the store."
    }
}

I have tried to check whats different between User A and User B, but all the permissions, properties, metadata etc seems the same. I can not figure out why only one user is able to read admin calendars. I tried to go through the documentation and nothing is mentioned about this scenario.

FYI, User A and User B can access the each others personal calendars when shared. Its just when reading admins seems to behave differently.

Do any know what exact permissions/ claims are needed to read the tenant admins calendar. These are the permission I granted the user in Graph Explorer

Thanks for your time

Vijay

Answer 1

There is nothing special about a tenant admin calendar per se. Are you sure the User B has the correct delegated perms? Can you verify and post here what those are