Question pixilation not working properly

i have a game i want to be pixelated, and for the most part it works, but the higher the cameras resolution the blurrier it gets, the pixels being maped onto a render texture which is on a quad and the camera is pointed at the quad. the objective res is 480x270
example:
960x540 camera res
3840x2160 camera res
its not super noticable but when switching between them, the crisper one looks so much better, and would add alot to game feel and polishedness lol,
what is causing this and how do i fix it?

 

How do you pixelate it?
What code or shader is used? Post processing? Blit?

 

i have a camera for the player obviously, that has its output texture set to a render texture asset

the render texture is also set to 480x270
then the render texture is used on a material which is attached to a quad

you can see the scene in the bottem right and the quad in the top left
then i have a camera set to look at the quad

 

Do you use the pixel perfect camera setup?

 

idk what that is so no
srry

 

Google it. Mainly used for 2d, but it makes sure no filtering of textures is happening. Now it probably has some