Check Prey's log & compare to the event log wake timings…
I don't think there is a 60 minute interval for Prey so check what is set in the control panel. Change the interval & see if that makes any difference (Prey will need to run to pick up the change, so either be patient or
force Prey to run).
Auto connect can be disabled in the config, but that limits the chance of getting data back to only when someone has setup a network connection.
The simplest way to test if it is Prey is to uninstall it & see if it stops, unless you are willing to try to edit the config & control panel settings.
Drew