Why does pen clipping produce jagged pixelated edges?

Question

Adobe Photoshop

Good afternoon!
I clip with a pen, press "Selection ...", make a layer mask - and this is the edge. This was not the case before.
What is the problem and how to fix it?

Answer 1

That's it, I figured it out - the layer somehow had a Dissolve blend mode, changed it to Normal and the edges became normal.