This is when you forget the built in apps and move to a Roku or Fire TV stick or box.
I have an LG 55UH6090 and a home theater Sony Dav-hdx576wf
My problem is I'm able to hear my tv through my home theater but when I try to open an app for example you tube, I still hear the cable tv channel through the home theater.
I have a complicated setup as nothing seemed to work for me. At first I had my HDMI cable from my cable box connected to the TV.
And from my home theater I had an HDMI connected to the HDMI arc on the tv. That didn't work, in fact I never got any audio at all not even from cable television.
So then I added an optical audio line from the receiver to the tv and still no sound at all not even with regular tv/cable
Lastly I add rc cables(red and white) from the receiver to the cable box - this now allows me to hear the tv/cable through my home system but it won't alternate sounds when I click on an app such as Netflix or YouTube. It just keeps playing what channel is on the cable box.
I have everything connected still hdmi arc and optical cable just because nothing seems to work I've disconnected one and left just the other to see if maybe it's a problem with both connections interacting is a defective way and nothing all out of options here please help