On my site, I’m importing posts to a custom post type with an XML file. After the posts have beeng imported it looks like some of the original images are broken. Please see attached screenshot:
https://monosnap.com/file/NS5uJBFYzhg1xzB2Qh5GnxW16B4A8N
After resetting image via Smush, the image is restored back to normal.