False alert? "Broken trust between computer and domain"

Since we first implemented ATA a few months ago, it's periodically had an alert about one computer or another with a broken trust relationship.  However, when I follow up on that alert I can find no sign of a problem with the computer.  I don't see anything related in the computer's event logs, logging on with domain credentials works normally, and running 'test-computersecurechannel' in powershell returns true.  

Any idea what causes this alert, and is it strictly a false alarm or is there some action that we need to take?