Just a quick update. Managed to fix the issue. I reset the units back to the factory setting, paired the device with another working unit then using a Ethernet cable connect to the web interface (192.168.1..2) switch off the WPS settings, changed the security key to one used by the other...
Thanks I try this - I will reset the zyxel units to the factory default first, retry and if that doesn't work I'll use the utilities to try and rename them.
Does anyone have experience of mixing tp-link tp-wpa281 and zyxel pla4231 powerline wifi adapters on the same electrical wiring.? I'm having problems getting them to talk to each other - the property is an old rectory but with modern UK standard wiring - the TP-link units synchronise ok but the...