Monitors have a fake HDR problem
Sometimes it’s just Windows’ fault
A major caveat to all of this HDR talk is that, even after years of work, updates, and readily available calibration tools, Windows 11 doesn’t handle HDR as well as one would hope.
First, you need to make sure HDR is enabled in your monitor settings and within Windows itself. You should also run the Windows HDR Calibration app to fine tune your settings. But even then, issues can crop up. A quick search on Reddit for your monitor’s name/model followed by “HDR settings” will likely turn up all sorts of threads and replies where new monitor owners are pulling their hair out.

Jon Martindale / Foundry
And then there’s Windows Auto HDR, a neat OS feature for gamers who want to play older games that don’t have HDR support on monitors that do have HDR support. It effectively tone maps the SDR signal to better fit an HDR display’s capabilities. It’s not as good as native HDR support, especially with games where the look was supposed to be flatter, but it’s a nice-to-have option for supported games and monitors.
Suffice it to say, your HDR experience will vary depending on your specific monitor, the hardware within it, the monitor’s settings, your Windows settings, your eyeballs, and your personal tastes.
HDR isn’t black and white. Some monitors are much better at displaying it than others, even if they all say they support HDR. Ignore the vague “HDR10” and “HDR supported” and “VESA DisplayHDR 400” terms and marketing materials. Look at the raw specifications. If HDR matters to you, make sure the monitor you’re buying really has the brightness and hardware to power it. Don’t just take a manufacturer at its word.
Further reading: The best monitors for 4K, HDR, and more