In an on-premise TFS (Team Foundation Server) 2017 environment, we are unable to find a few groups from Active Directory in the Approvers field of the Release Management system despite the fact that the vast majority of groups and users can be selected.
I initially suspected the issue was due to security, but even after adding the groups as project administrators the system continues to prevent me from finding them in the dropdown.
My next step was to ensure that the groups had a sufficient Access Level, but after granting them the VS Enterprise access the issue persists.
Even though I can find the group in TFS at the Collection Security level, I ruled out an Active Directory Sync issue by running the Active Directory Sync job via the TFS QueueJobNow webservice and waiting for it to complete.
That leaves the following potential issues addressed and verified: TFS Security, TFS Access Level, and Active Directory Sync.
What am I missing here? Is there another level at which I need to grant access for this group?