Weird 'artifacts' inside a color shape/closed path

[Juan Cano]

Hello; I am working using icons I download from Getty. I don't know if this relevant but whatever. I'm on a Mac with Monterey. Newest Illustrator.

In this icon, the grey areas are not strokes but shape paths. The insides where originally empty. I want to color the icon so I did "Compound Path > Release" to be able to color the empty areas. 

I made one shape a color and turned the Opacity to 75% and I get these weird straight line edges/artifacts. You don't see them if color at 100%. The pale yellow areas are also a color at 50% and I don't see these artifacts.

This has happened in more than one icons, and icons do not come from the same set/file from Getty.

You ever seen this? It looks like the path is doing some type of overlapping and creating these shapes, but if you look at it in the 'outline' view, you see it is just a clean pth. No issues.

Weird hu?

 

[Ton Frederiks]

Those are Preview problems caused by the GPU Preview.

Try Cmd or Ctrl E to switch between GPU and CPU.

[Juan Cano]

Ah!!!! Well, that's good to know. Thanks for the tip.

[Ton Frederiks]

GPU preview is fast but sometimes not very accurate.

It should not affect export or print.