Thanks for your reply. It's very enlightening.
To start, I have an LG OLED so HDR isn't something I've never seen before. I've just never seen it behave like this before on a Faux-K projector.
I'm attaching a video clip of the phenomenon I'm seeing from a firestick 4K. The projector is set on HDMI port 1 with HDMI 2.0 enabled. Standard color profile and highlight mode selected.
Notice at 6 seconds and at 18 seconds, when HDR kicks in the screen dims significantly. This is projected onto an ALR PET Crystal xyscreen. In complete dark with no ambient light, it's incredibly hard to see. Somehow my cellphone camera is able to pick something up, So here it is.
This is tested on an 8K HDMI (2.1) chord. I've also tested this with two different HDMI cables as well. Same darkening issue. CONNECTION: Shield box to HDMI to projector. The firestick is plugged directly onto projector. Both in HDMI port 1.
Display settings shows I get 4K @ 59.9fps (not exactly 60fps).
No HDR out of HDMI port 3/ARC.
I've tried doing some calibration on dynamic range using YouTube videos where brightness controls the blacks and contrast for the whites. But this doesn't help at all.
I'll try plugging in your settings and RGB values and see if it makes any difference. BTW, feel free to pm me over on XDA since I'm unable to pm you here without x-amount of posts.
I really hope this isn't due to bad hardware.
I'm really thinking about buying a Roku ultra to to see if HDR works properly. Or if the issue is really isolated to these two devices.
I've tried playing some 4K HDR video on YouTube, but I don't know if they really are HDR enabled despite being from the "HDR channel"