Help S8 + Android 9 = can't see Display P3 images


I tried the latest Google Photos app, Google chrome, Samsung Internet Browser, and phone's own photo app.
No matter what Display profile I choose, all wide-gamut content is treated as sRGB and won't display correctly.

Tested with the red square at
I can see the logo using my friend's Galaxy S10, but not with my S8, which should also pass the test.

Is this a known bug? Is there any trick I can try to make this work?
Also, "Use sRGB mode" in Developers options don't seem to work properly for me. Defaults to OFF, which, in theory, should be OK.

Should I try a fresh install?