Entries in suspect_pages but checkdb shows no error
So I wrote to Brent Ozar and this is the answer I got from him. It's the best answer I've got so far so I'll put it here:


  here's exactly what I do when SQL Server reports corruption:
  https://brentozar.com/go/corruption
  
  Suspect_pages doesn't do false positives, but the corruption may have been repaired since (or may have only been corrupt temporarily, like if storage had a transient error when you went to go read it the first time.) Definitely follow that checklist and star tthe support call with MS.
  
  Hope that helps!
  Brent