Just checked on the Now app on our 2020 LG GX, running over WiFi, and with Boost.
The Good Life was showing.
It pixelated for a second, but then locked on and was fine, or as fine as an SD 4:3 programme can be.
I tried some other live channels, and most came straight up, but 3 had initial pixelation, even including Sky News.
So nothing unique to UK Gold.
Have you tried powering down your router, right off at the mains, waiting two minutes, and then powering it up again?
Followed by doing the same on your TV?
Worth a try to see if that fixes it.
What about unplugging the TV?
You could try clearing the cache.
Worst case you can set it back to factory settings.
Still the same after a factory reset?
Report the fault with staff on live chat, just make sure to click “chat online”.
Wow, I see what you mean by pixelated 😢
I did see the green/black thing on our LG GX, when it was cycling through the artwork in the screensaver; one picture, once, turned green halfway down, and this persisted until the next painting came up. And when the affected painting came round again, it was fine.
So it does look like the green/black is something LG sets can do when they glitch. But I have seen nothing like that pixelation.