Screenshots are Low Resolution with imported to Storyline?

Hello, I am new to e-course authoring and have been trying out Articulate Storyline.

One issue I am having: whenever I take high-resolution screenshots, then import them into Storyline, they become pretty low-resolution. They are blurry, and I fear my learners will find it unpleasant & illegible. Even when I enter preview, they remain blurry.

Am I doing something wrong? Is there a way to keep the screenshots high-res?

Thanks!