FYI, this SW9 file will not play (TV says video not supported) if I have 4:2:2 on with AVR in play but plays at 4096 x 2160 with 4:2:2 off.
I’ve moved to the N2 today under 9.03 and the Elysium and Interstellar 4k trailers do not play. I have no doubt that if I upgrade to the 0831 nightly, this will fix it. Should I leave it on 9.0.3 so we can figure out what is going on? dispinfo here whilst playing (no sound, picture) the Elysium trailer http://ix.io/1U6Z
P.S The other 4k trailers (Sony, LG Chess and Astra) all still render in 1080P.
I also had problems with black screens and high bitrate 4K trailers in the past.
The solution was to exchange all of my HDMI cables with premium certified ones.
Thanks. All of my cables are the exact same brand and high-quality slimline ones. The trailers that don’t play on my C2 under 9.0.3 will play with the nightly 20190831 suggesting the issue is not cable related?
I’m going to give this a try today, nothing to lose. I’ll grab a HDMI 2.1 certified cable and connect it between the C2/N2 and the TV’s ARC input to see if it makes a difference as the TV displays the video correctly when using the integrated DLNA feature.
The plot thickens. I purchased 1 x 4k cable and 1 x 8k and compared these with my existing high-speed HDMI cables. Sadly, no difference. Here is where I’m at.
N2 via AVR. Both 9.0.3 and 20190831 play all of my 4k HDR test files (Astra, LG Chess, Life of Pi, Sony Camping) in their correct resolution however it will not play the Elysium, Interstellar or SW9 4k trailers producing no picture and sound. If I connect the N2 direct to the TV though, I can see why. The video is playing back (poorly) in a windowed mode that the AVR cannot pass seen below. Tried 20190905 without luck as well.
C2 via AVR. Both 9.0.3 and 20190831 which I’m running now will not play the Astra, LG Chess or Sony camping in 4k instead choosing 1080P. However, Life of Pi 4k HDR as well as the others that the N2 will simply not play at all like Elysium, Interstellar or SW9 4k trailers all play fine in their native resolution. Go figure.
For now and to keep the family happy, I’ll just stay with the C2 on 20190831 until I can find a resolution for the N2 playback issues with some 4k content.
You have overscan configured in Kodi.
Thanks but could you be more specific? A quick search of my guisettings.xml (same one used on working C2) reveals 44 instances of the word ‘overscan’. Which bit am I editing?
Check the entries for 4K resolutions.
Should I remove all references to ‘overscan’ in those sections?
Yes, you need to remove them.
Dang, didn’t work. Can I just delete the gui file and let Kodi create a new one?
Kodi already has its own default file, so you can delete it (or just rename it to something else) and restart Kodi.
Thanks. Sadly, that did not work either. I’ll try a full factory reset and the latest nightly and see how I go.
I seem to be going around in circles. Both my N2 and C2 do not like my STR-DN1060 at all and give me a blank screen when playing the Elysium, SW9 and other trailers. If I connect the HDMI direct to the ARC input of the TV, the video now plays in 4k however the audio is stuttering.
I’ve tried every combination of screen settings in the AVR’s menu without success. Anything else I can try?
You can limit the color depth to 8 bit or force 4:2:2 output in System/CoreELEC settings.
These settings are available in nightlies only.
Thanks. For now I rolled back to LE 9.0.2 and everything is working fine. I’ll play around with my N2 as a separate issue and won’t screw with my main system so I don’t start walking with a limp! 
I figured out the my Sony STR-DN1060 does not pass HDR with no upgrade in site and this seems to be a big part of the problem, at least with CE. I still don’t know why my C2 plays the Elysium and other 4k trailers on LE but not CE but at least I know why the HDR clips are not switching.
And yes, I have confirmed that 4:2:2 output settings does in fact work (thanks) when the Odroid is connected through my AVR but for now, I think the best best is to just keep my Odroid connected direct to the TV and use ARC for the sound to the AVR, at least until I can upgrade to the STR-DN1080. 
The C2 doesn’t support HDR, only 4K, that is why it works.
The Elysium trailer and three others that cause the blank/black screen issue are not HDR.
