If your problem is the intermittency of the internet signal via cable / wired, and the reception via WIFI signal is "off", follow this saying and be happy:
https://www.theraffon.net/~spookcentral/scblog/tcp/2019/07/10/lg-smart-tv-unknown-device-is-disconnected-fix
Basically you will turn off the WIFI module of your TV - which is responsible for generating the problem on the Ethernet signal too.