EdgeRouter X will not power from UniFi AP Lite PoE

I'm having trouble powering my Edgerouter X with POE from my Unifi AC Lite. I've turned on POE in eth4, and configured everything correctly as far as I can tell.

Now, if I set them up the 'proper' way, with the 12V charger powering the Edgerouter X, and the 24V POE with the Unifi Lite, everything works entirely smooth. However, trying to even power the Edgerouter X with the 24V won't even make the unit turn on.

Modem Cat6-->LAN Input of POE adaptor
POE slot Cat6 on POE adaptor-->eth0 of Edgerouter

Still no signs of life, let alone trying to plug the Unifi into eth4.

Could something be faulty or am I missing something?