Sorry to bump this back to the top, but I'm still having this issue, and it's also happening on a new APU 1.C board running the latest version of pfSense.
If I cannot resolve this issue, I would like to at least know when a pfSense box is rebooted, is there a way I can be notified of a reboot? Sendmail? What about having the pfSense box open a url on my website, which I can code to notify me that it's been opened etc etc?