I have a Windows 10 device 10.0.19043.1766. We use a proxy server for all of our internet connections. To install Prey I tether it to my phone and install Prey. It installs and Activates. I can send a message to the device and it all works. I then edit the Prey.conf and under the Proxy Server option I add our proxy server eg. http://1.1.1.1:8080. I reboot the device and connect it to our internal WiFi. When I check the Prey.txt it’s not using the proxy server and the device cannot be contacted through the web GUI. I have tried swapping from https to http under protocol but same problem.
Bit more of an update. I finally got it working through the proxy. But 2 problems:
1: The Location feature does not work when you have the proxy setting in the prey.conf
2: When the proxy feature is enabled in the prey.conf it will not work when you go home that does not require a proxy.