I own a number of 4K UHD BD movies that I’ve digitized and put on my Jellyfin server. I’m running Infuse 6 on an Apple TV 4K connected to an Epson 5050UB projector. Infuse shows the movie as “4K HDR”. However, when I play it, I only get SDR (as reported by my projector). I confirmed that HDR works fine in Netflix and Disney+, so this seems to be an Infuse specific problem. I searched around the web and some people suggested restarting the Apple TV. I did that but it did not help. I also tried playing several different 4K HDR movies from my Jellyfin server, all with the same results.
Match Dynamic Range and Match Frame Rate are both turned on in Settings.