Images "cut" into strips after conversion HTML to epub in calibre

Hello,

I converted and HTML file into an EPUB with Calibre.

Some of the images on the epub file however seem to be missing chunks (there'll be a white strip going across the image or a section of the image seems to be missing as if it was cut out.

If I open the HTML the images look fine, also the source images in the HTML are fine.

I've also had the same thing happen when converting some PDFs to epub.

Does anyone know how to fix this?

Thanks!