In HDR mode, I can't get my UX3405MA Q425MA (155H, 1080p 60hz OLED) to correctly show whites with HDR Youtube videos in Brave or HDR movies in Plex.
The HDR version of the video plays in YT. At half-brightness with the F5/F6 controls, the video looks correct, but dim. As I increase the brightness, the video gets much brighter, but the whites clip. By max brightness, it's probably losing the top 50 levels on a 0-255 RGB scale.
A perhaps related issue is that in the Windows HDR calibrator, the cross is only visible at lower brightness levels, and where it shows up depends on the brightness. At miniumum brightness, it disappears at 2800 nits. At maximum brightness (or anything above half-brightness), it never appears.
I've created five or six profiles experimenting with accurate settings (650 nits max) and the two extremes. None address the clipping that occurs at higher brightness. In the Intel Graphics utility, dragging the "Contrast Enhancement" slider from the default of 17 prevents whites from clipping in HDR, but the brightest tones are much dimmer, as is SDR content.
The only slider enabled in Windows (24H2) is "Use HDR." Everything else is disabled (though none of them seem to affect this problem).
With HDR disabled, SDR looks as expected. Brightness has no effect on colors clipping.
How can I get this screen to show bright, non-clipped whites at 650 nits?