9-spliced button scales weirdly?

I'm trying to make a custom button sprite for my game, and I'm running into a problem with the sprite getting squished.

This is what the base sprite looks like:


This is what it looks like in-game:


As you can see, the circles get vertically compressed/horizontally stretched. If I decrease the resolution of the base sprite, it doesn't get stretched, but it looks pixelated. A higher resolution looks smoother but stretched.

Is there a good way to solve this problem?

 

Solved this by changing the Pixels Per Unit in the sprite inspector to a higher number. I doubled it for my solution.