Daily Catalog Backup has started running Hourly

I'm running Netbackup 7.5.0.7 on a Windows 2008 R2 server...   This instance of NBU has been in our environment for about 10 years now...and we've almost migrated everything off of it to Commvault...   But, it's still around for EV backups.   

Recently, my daily Full Catalog backup has started running every hour and I can't seem to determine why this is.    It's scheduled based on Calendar, not frequency, to run daily...and this has not changed.   But, the job will run every hour unless I kill it.    

Any ideas as to what may cause this or insight into how to troubleshoot would be appreciated.

Thanks,

Alan