I have an AV1000 unit plugged in my son's room and paired with an AC1200 unit that is tied directly to my modem. We set this up 2 months ago, paired them according to instructions and while the performance was not fantastic because of non-ideal wiring in the house between the two rooms, we did get a functional network connection going. My son was using the ethernet via the extender plugged in under his desk and would get about 25Mbps download speeds. Today, his signal became flaky and he realized he had been moved back to the house wifi signal, which doesn't work well in his room. When we checked for the tp-link ethernet network, it isn't there. Instead there is a choice 'Unidentified Network' with the subheading 'No Internet'. We unplugged his unit, replugged it in, repaired it with the unit plugged into the modem and that changed nothing.
How do I troubleshoot this??