As R1D2 mentioned, first of all, you should ensure the network connectivity between EAP and controller. Check FAQ[1363] and check the below things: 1. Does the AP have proper IP address and gateway,...

Upgrade the firmware from www.tp-link.com too.

It shouldn't act like this. Can you provide more details about your topology including the subnet assignment

Advantech wrote So it seems that the US firmware comes with a hidden gotcha... the inability to change firmware... There was no warning on this firmware, which is pretty outrageous thing to conceal...

Reset the CPE510 to factory default. Try it again following the QIG. Use Firefox or Chrome. Don't use IE

If it still doesn't work. Then it is limited by the upstream network restrictions. It has nothing to do with CPE.