I have the latest Optoma 4K projector I'm running an ultra 4K fire stick and a PS4 Pro through a 4K Onkyo receiver pass through and I cannot get HDR choice in my projector settings it only shows in 1080p
Does the Onkyo receiver support sufficient HDMI bandwidth to handle 4k(60?) HDR? If so, you may need to go through the projector's menus to find options to enable 4k HDR / 4k60. I recently bought a 4k TV for use as a secondary monitor and it took me a while to figure out why it was only giving me 4k30 without HDR. Had to dig through the TV's passable UI to find the input configuration page and enable HDMI 2.0 on a per-port basis.