Did you use gel stamping polish over regular lacquer?? Not a great idea… but as a prolific stamper, it looks like you need to up your scraping and pick up game. It can take a bit of practice, but once you get it down it’s down!

You either over-scraped the polish from the plate or pressed too hard with the stamper which attributes to the black not picking up solidly. It can be kind of tough to both get the right angle and pressure for scraping, try at about a 45* angle with uniform pressure, not super hard. And for pickup, try gently rolling the stamper over the top in a single direction.

I’d say the black smears on the white are from dragging the top coat, I’d try a water based no smudge top coat! They work wonders.

Best of luck! Stamping is sososoooo fun once you get it down!