How to get spritesheet to clip correctly?

I’m trying to make a pixelized 2D game. I had to look at several guides to figure out how to get things to appear with pixel-perfect precision and it worked, but now I am having an issue where my sprite animation isn’t clipping properly: 169685-cuv01oehgi.gif

The boundaries appear to be drawn correctly on the spritesheet:

Sidenote: the “Pivot Unit Mode” keeps changing to Normalized, no matter how many times I change it to Pixels like so many of these tutorials tell me to do.

I’m also using the Pixel Perfect Camera, in case that matters—Assets Pixels Per Unit 16, Reference Resolution (X 256, Y 224), Upscale Render Texture unchecked, Pixel Snapping unchecked, Crop Frame (X unchecked, Y unchecked).

It’s somehow worse than I thought… I changed the Pivot positions all to Center and this happened: 169689-bbwmtv4jqr.gif

I thought I had the pixel-perfect feature figured out too, but I noticed stretching in the checkerboard tiles when I resized the game window. Looks like it’s probably happening at the gaps between the tiles. How can I fix this?