I have both ,s23u and upgraded to s24u because of the preorder deals here in uk.
I noticed few issues with my s24u's display:
1. A slight delamination at the bottom of the screen to both corners,exactly the same as s23u had(returned 2 units and the 3rd was perfect)
2. Brightness on adaptive or not ,indoors, is lower than s23u' display
3. Muted colours on s24u,vivid mode looks the same as natural
4.Grainy screen ,visible on low Brightness, especially on darker colours
On the last issue(4), I took some photos where i had both phones on min brightness, on exact same grey background, in pitch black room, used night mode to shot the pics.
Both phones side by side and i straight away i noticed that s24u looks grainy than s23u.
The photo of s24u's display appeared not grainy, but it has some weird pattern, some diagonal lines(check photos) and 3 more visible horizontal lines.
Can you please check if your units has these issues, including delamination
