LG G4 OLED Display Issues

[JohnGreenan]

Hi,

I'm having issues with my Windows PC changing refresh rates and switching between SDR and HDR. I have found that using a hardware splitter helps, not splitting signal just using hdmi in and hdmi out.

HDMI 2.1 Spliiter

Is it possible to do what this splitter does with software, registry change? I have tried the CRU but I'm not sure I'm using it correctly.

Windows 24H2, i3 Intel® UHD Graphics 730 to LG G4 Oled TV, HDMI 2.1 to HDMI 2.1.

Specifically I'm using Kodi to play MKV's so its trying to change refresh rate then switch on HDR (for HDR10 mkv), at this point it manages to change to 24hz but then fails at the HDR switch and drops back to default display 4k@60hz, Kodi minimises and wont maximise and I have to force close.

I can also connect direct to hdmi in on soundbar then to tv and the refresh rate change and HDR switch works, but then another problem is any TV input switch or resume from sleep Kodi again minimises and I have to force close.

Just trying to get my head round it all and I get that this might be a software issue, but I just don't understand why a hardware splitter helps. Its a new TV, nothing changed on my PC which worked flawlessly on an LG B8 OLED (HDMI 2 ARC only) - LG G4 is HDMI 2.1 and eARC.

I did try and ask on Kodi forums and one of the Devs said it was a timing issue on my system - "On your system the timing is just right to make audio come back just a bit late and make Kodi fall back to DirectSound, which doesn't passthrough high resolution formats" which kind of makes sense as sometimes I have to change sound back to wasapi.
I see the same behaviour in MPC-BE when I have refresh rate change on and SDR to HDR on.
Makes me think it might be the intel audio driver causing my issues, but I used DDU and tried 3 different drivers back to 07/2023 and still same thing.

Lastly, changing from 8bit to 10bit seems to work but I'm then at max of 30hz refresh rate, I have 60fps videos that look bad at 30hz.

Attached is details from IGC. I can show video if needed as LG TV has a good overlay showing realtime the HZ, Resolution and colourspace.

Thanks for any help!