Thanks @Kevin_Z. I used the TP Link utility to configure the extenders, pressing the WPS button didn't work. I've unpluggeg the TP Link devices and the main router has been stable for 24 hours. I...

I've connected a TL-WPA4220 to my Virgin Media Superhub 3, I set the wirerless SSID and password on the tp-link extenders to match my Virgin Media network. Everything seemed to be working fine but...