Internet connection OK, but router not connecting so no WiFi

[Andy_H1]

Since Monday 20 January 2025 router light flashing amber and not connecting. Following lengthy call via Chat (using mobile data), identified that fibre connection was OK (plugged ethernet cable direct into ONT) so concluded the fault was a faulty router. Replacement router arrived Thursday 23 Jan but exactly the same issue. Router fails to connect (even after ONT switched off for 20 minutes and reset button pressed) - constant amber flashing light. Can still connect laptop to internet via ethernet cable plugged direct into ONT, but doesn't work if plugged into an ethernet port on the router. Tech team on Chat have apparently referred the issue to the back office team, but I've not heard anything further and I keep getting messages from TalkTalk to say it's been fixed! (It hasn't!).

[KeithFrench]

Which Ethernet port in the router are you connecting the ONT to, it must be the red WAN one? When you tested the ONT with a PC, was that using the same cable that normally connects to the router? If not, can you please try another Ethernet cable?

What firmware version is on the new router? Who provided the Full Fibre, was it Openreach, CityFibre or another company?