Allegro - Stuck with red DRC status, nothing in DRC Report

My DRC status is still red, indicating a DRC error:

But when I run Tools > Update DRC, then Tools > Quick Reports > Design Rules Check (DRC) Report nothing shows up in the window. Same with Tools > Quick Reports > Design Rules Net Short Check (DRC) Report.

Is this a bug? Or is there somewhere else I can check to see if any design rules are broken?