I think I found the reason for the grainy overlay of the S24 Ultra and perhaps all S24 series.
Simply try "Circle to search" CTS. On my phone, the screen starts glowing with tiny grains in the entire screen. Kind of little stars dance on all over the screen.
The pattern of these grains are very similar to the pattern that I see when I look on dark colors like plain gray color in a dark room, but instead of they glow and dance, they statically cover the entire screen like a glitch and it is always present no matter what you have on the screen. This can also potentially reduce the display quality showing content on it.
I tried to take a screen shot when you activate CTS. I hope it to be clear. But nevertheless, you try it and see the effect on your phone.
If this is a glitch because of this CTS functionality, then it can be easily solved with an update. I hope Samsung to see this post. I will also try to convey them in the members app.
