Some LG models typically at the higher end, you can disable wifi. There is a switch that appears on top of wifi. Most LG tvs don't have the switch.. To disable wifi, you have to connect an ethernet cable at the back.
We have the same issue. My TV is UJ7500. I gave up and hardwired the TV. Tv wifi cannot detect the wifi router that I placed mere inches from the TV.... Any fix would be appreciated. Sent from my LG-H990 using Tapatalk