For some reason I can't find this picture through search. Why is that? It has the hankuri tag and crazy_eyes tags. Yet when I search for hankuri and crazy_eyes, this picture does not show up at all.

safebooru.org/index.php?page=post&s=view&id=2706052

Found.
I used the "crazy_eyes x_(rockman)" string and found that picture. Problem solved?
Most likely, the server was doing something else at the same time. In the past, tags have had delays in aggrogating content.