These rigs are a pain. So I can't be sure if this can be fixed.
But let's try a thing. Most TVs will not pass any HD audio over to Optical so I'd try an Optical link to the soundbar and maybe that will mute it when playing from the HTK.
Or get an HDMI audio extractor (so many so I'll link to one with no intent of guarantee that's the right one) to put in line with the HTK to HDTV to drop the audio out. Example:
Sorry about the fact I can't be sure what is the right way to work this one. I could write about receivers but I understand you want to try to fix what you have.
Hi, I have been in touch with LG about my problem and they told me it looks like both items share the same infra red channel and nothing can be done.
Here is the problem as well as the products.
I purchased LG LHB645N 5 1 1000W 2 N 2 BLU RAY HTK and am happy with the product although it would not play 4k movies so I purchased LG UBK80 HDR10 BLU RAY PLAYER and LG SK5 360W 2.1Ch Sound Bar with DTS Virtual X Sound for my 4K disks. Three products shown but only two are the problem. The sound bar and the Blu Ray home cinema system are the two.
I want to watch a normal DVD/Blu Ray so turn on that player put in the disk and start. when its starts to play, you get the sound come through the 5:1 surround system with the player but at the same time the sound bar plays the audio. I turn off the sound bar and off goes my blu ray player also turn the blu ray player back on and the sound bar also comes back on causing the same problem.
My Sky box is connected to the TV via HDMI cable and plugged into HDMI 1 on the TV
The sound bar is plugged into HDMI ARC (2) on the TV using a HDMI ARC cable.
Both Blu Ray Players are connected to a 4K HDMI Splitter which is plugged into HDMI3 on the tv. The 1st thing LG help told me was it was a problem being caused because of the 4K splitter. The problem is there whether I use the splitter or not .
I have been muting the sound bar to be able to watch disks but that for some reason turns of the surround on the player.
I do hope someone out there understands this post and is able to help, and any help would be graciously received.