We had 2 repositories CCode and VCode, VCode was visible to me CCode to everyone else. When a differential I commandeered from someone else got closed by him. He got the notifications but could not access the differential. The only way to fix this was to give visible permissions to VCode.
Note: I did a clone of Code because after the migration I could not see any of the commits at Code and my first thought was that the database was corrupt.