Regression in Browser Rendering screenshot

I'm not sure when it started, but @cloudflare/puppeteer's screenshot() now produces images with black scrollbars (picture attached). I use https://github.com/cognitom/paper-css to generate A4 borderless "prints." If I use pdf(), the black scrollbars don't appear. Curious if anyone has experience this, or know how to fix this using CSS? Also, I'm just curious: Is converting PDF to PNG/WEBP more "expensive" than letting Puppeteer do it natively? I think I can do that to work around the regression.