Yup! This is the chrominane overshoot test like the one I linked to in my thread. C9 flashes in this, but as I wrote earlier, less than the Metz OLED, and I haven't noticed flashing in any content. Watching Godzilla 2019 right now in 4k HDR; blacks aren't black in this either, which is an artistic choice, but there's no flashing, which is what should happen for you too once you set accurate black level setting.Ok so I tried reducing the brightness and kept oled light at max at the time nd credits of maleficient 2. So when I got the brightness to 45 the grayish went away and it was black. But there was flashing. I also tried the below link where it is mentioned that tv’s having this fault will show flashing when colours are changing. I also wanted to make sure it was not the shield so connected the HD directly in the tv and it was the same
So now that you found out your accurate brightness setting for SDR, go back and check the problematic content. This video does show flashing; Vincent and John also mentioned that such tests still show flashing in 2019 sets, but they didn't see it in content either after calibration.
You'll have to calibrate you HDR black level too. Use the avsforum HDR calibration slides, or as suggesred earlier, use the LG demo video. Pause it and check black level in that. If you can find a fade to Black in that, then pause when the screen entirely black.
Btw, Sony 2019 sets are worse than LG in this. Just check Vincent's AG9 review.