Pre-backup task is running every five minutes with nonstop backup; was not set to do this

I have two backup jobs. One is a standard incremental partition backup to a shared folder on another machine on my network. I have added a pre-backup task to run, which is a little application that wakes up the other machine (wake on lan) prior to commencing the backup. This backup job is not on a schedule; it runs only if I manually start it.

My other backup job is a nonstop backup to a 32gb SD card plugged into my notebook. What I'm seeing is the pre-backup task from the manual partition backup job is being executed every five minutes just before the nonstop backup does its run.

These two jobs should not be related, and nonstop backup offers very few configuration options, and none of these are a pre-run task. Why is this happening? How can it be fixed?

Thank you.