Actually a TL-WPA7517 kit (not listed in Model list).
Have used an AV500 system successfully for many years, but wanted to fill a dead spot in the house with a WiFi extender so bought a TL-WPA7517 kit to upgrade it. When the PA7017 is connected to the router, the WPA7517 will not maintain a powerline connection (briefy connects then powerline light goes off after ~13 - 15 seconds). This repeats every 30 seconds or so. Plugged both in without connection to router and powerline connection stays lit. Paired the two WPA7517 sucessfully while not connected to the router and can then access the configuration. Upgraded the firmware as per guidance but as soon as I plug the router cable back into the PA7017, the powerline light goes out on both boxes and the repeating gain/loss of powerline connection starts again. Router is a Netgear WNR3500Lv2, firmware V1.2.6.00_50.0.106 which is the most current (I think).
By perseverence I managed to get the router and WiFi synced with WPA but still the same probelm of not maintianing the powerline connection.