Artifacts when using different zoom levels

I was doing this halftone lines effect and the way it looks at different zoom levels differs a lot. In these two patters form, but in others lightness levels even seem to differ, for example there's some white in the eyes. I feel like mipmapping or whathever affinity does, is not kind whith this particular effect.

My effect stack looks like this:

gaussian blur layer
threshold layer
line shapes with blur effect
Curve layer
Image