Not sure if the rep is still around but I'll ask anyways.
I have AV500 nano and wifi kits (TL-PA411Kit / TL-WPA4220T). From the beginning I have gone into the utility software and ticked the box to set them all to the network name homeplugav but Im having an odd issue with them in that they will out of nowhere all drop connection, I have to go to each one to find out that the box to set them all to HomeplugAV has been unticked as the traditional pairing instructions do not work.
The original part of my house is old and there is a newer extension. The base plug is plugged into the newer part of the house along with 1 of the wifi plugs, and the other 3 are plugged into the older side, i dont know if this makes a difference.
I dont know if RMA'ing them would make a difference.
I bought them elsewhere, but the warranty would be with TP-Link directly I assume.