I was able to resolve this by checking the option in the sync settings to "Perform a full sync each run". I then manually ran the Azure sync task many times until it was finished syncing the users who were in that AD group. Finally, I unchecked the full sync option.
A couple days later I had a few new student accounts to sync. That completed fine without having to check the full sync option again.
A couple days later I had a few new student accounts to sync. That completed fine without having to check the full sync option again.
