JSON Contact sending [] as payload.

I have defined a JSON Contact with 2 Associated Syslog Rules.  This worked for quite awhile then started sending [] as the payload.  I successfully tested Contact using test_alert.php and see a full JSON payload.  Not sure how to debug from here.  Note, I did have an Alert checker also defined but removed it, so only the Syslog rules remain. I have recreated the Contact to no avail.  I also tested my Syslog rules successfully with an Email contact.