Well I decided to change my screen protector today and have a look on "clean" screen. I noticed I have 2 dead RED sub pixels.

There are kinda in the bottom center part of the screen. Barely visible, but now my OCD kicked in. It seems I will ask for repair or look directly for 15 Pro Max.
Edit: I'm investigating now more deeply. It's so weird. If I shift like some mm. my POV the pixel is working, but other appears (call it 3rd) next to it with that shifted vision. If I go stright up (90 deg), the 3rd is working, but the other becomes dark dot. It's they are not working at specific angle. But with my naked eye I can't see it. Should be 100% with a magnifying glass like 3-4cm from screen.
Edit #2: For me this looks like some kind of microscophic dust inside. From an angle like I said they show on/off and even the green sub pixel on the same spot changes to dark when red goes visible ... and the opposite. So something is covering them up.
Seeing how the pixel layout looks makes sense