Beginner user: pixelated icons

Hi, I’m a new user trying to download free sample icons before committing to the paid version. I’m choosing the “pixel perfect” size for each one, but they’re always blurry/pixelated. The icons are being used on a Wix website. Any ideas?

Hi! Could you share any screen captures of the icons that look blurry? Does it happen with every icon or only with some of them?