how to make pixel perfect camera bigger without pixels stretching/compressing

was making a 2D 20 * 20 pixel tile palate rpg thing but every time I stopped the mane character random pixels would be stretched. I looked up why and how to fix It before I decided the best way was with the pixel perfect camera and it worked but for one problem, it was zoomed way in and when I zoomed back out with the "Assets Pixels Per Unit" It had the same pixel stretch problem.