My AV600 powerline WiFi extender has been working for at least a year but stopped broadcasting WiFi yesterday, no changes to my set up.

I have done a factory reset on it, at which point I can see it on my phone as a WiFi point to connect to, but as soon as I pair it to the home powerline adapter (connected to my router) it stops broadcasting a WiFi signal.

All the correct green lights are showing.

I have tried switching everything off including router, then bringing the router back online, the connected adapter online (and factory resetting it) then switching the AV600 back on , facory resetting it and pairing it but still the same problem.

Any suggestions please or is it broken? Thanks.