I’ve just discovered that my monitor of the last 2 years (HP X27q) supports HDR 400. Not great, but an improvement over SDR nonetheless, I’d say. Only problem is, when I enable it, the monitor begins to emit a very high pitch whining noise. It’s incredibly quiet, so quiet I didn’t notice it for a few days. But now that I know it’s there, it’s definitely there and I can’t go back to not hearing it. What in the world is going on with the HDR setting?
It could be related with non official ink cartridges that you’ve tried to use in your HP printer.
Just a wild guess…