Does this happen if you watch a movie on terrestrial TV?
TV speakers are not the best, especially due to the ultra thin style nowadays. What model LG do you have?
I assume you've checked for any software updates - this should happen automatically anyway though.
What will almost definitely solve this for you is buying a sound bar. They are so much better than standard TV speakers and there is a huge range in terms of price now, though you're best off with something with a few channels to handle dialogue and other audio.
If you don't want to buy something , are you sure you haven't missed an advanced settings option somewhere in the audio settings menu?
No, it doesn't happen if I watch terrestrial TV. It sounds 'normal' the dialogue and sound/action are equal to one another.
Which is why I suspect it's something to do with audio down mixing although of course I could be wrong. Even still, I want to remedy the issue.
I haven't checked for software updates, but I think it does this automatically.
The model is: LG UF860V
The missus reckons a soundbar would help, but after reading (briefly) on the net, it didn't seem to solve some users' problems. Others recommended 5.1 surround sound to sort out the low dialogue, but reports back on that seem indifferent.
There genuinely seems to be a problem with this soft dialogue, loud sound havoc. And it's only been around for what, the last decade or so?
When I go down the father in-laws, it's the same on his, and he has a receiver and Jamo speakers for additional sound, yet when we're watching late at night - the dialogue is really soft then bang the Jamo's wake the kids up as soon as there is a gunfight.
Never, ever had this issue on the old televisions, or even on terrestrial TV today, which is why I suspect it's something the sound engineers are doing when they are mixing down.
You ever heard of this problem before?