How to maintain Pixel Perfection on changing window size?

To give some context, my tiles are 32x32 each, the pixels per units are 0.32, and using a orthographic camera with the ortho width set to 4000 (1280/0.32(pixels per unit)).
This achieves the effect i desire, on the resolution i want(1280x720). I’m trying to make each ‘level’ have a static camera that captures the entire scene, and i’ve been able to get pixel perfection and also being able to capture all the scene thus far.
The problem is that as soon as i change the window size i lose the pixel perfection(altough i still capture the entire scene as i want).
If i use a console command to set the resolution to 1280x720 without having this window size, i’ll maintain the pixel perfection, but things will look kinda blurry.
How can scale things to maintain the 1280x720 screen look regardless of window size(getting black borders is not a problem, if this has to happen for some sizes)?
Constrain Aspect Ratio doesn’t seem to do it.