Some devices won't connect to broadband

[#1]

Hi All, new to this forum. hope you can help.

Ever since I upgraded to fibre only my pc will connect reliably to the internet via (router Sagemcom plusnet hub one). I'm using wifi with most of my devices tablets, phones, pc, firestick, wii (not all at same time) but even my TV now won't connect via Lan cable.

I saw something suggesting firmware upgrade may help... any other ideas.

Driving me nuts, grateful for any help.

Thanks

[#2]

I don't have a plus one router, maybe this will help

https://www.plus.net/help/broadband/#wifi-help

[#3]

Thanks, but already tried the plusnet broadband help and had an incident raised previously but no help. Also not only affecting wifi connected devices , can't get my TV to connect either via lan