What Triggers Hazel to Run?

So, I have had multiple times where it seems like Hazel doesn't run. For example, I'm monitoring the download directory for .PDF files (bills). I downloaded a bill this morning at 7:06 and Hazel never ran. I then went into the UI and wanted to test the rule against the file. It matched perfectly. Once that was done, Hazel processed the rule a minute later.

All in all, the file was downloaded at 7:06am but the rule didn't process until 7:15am.

Any ideas?

Export your rules for that folder, remove the folder from Hazel, add it back to Hazel then import your rules. See if things work after that.