[DNSB]

If the image is too big to fit on a page, nothing will keep it from splitting. You might want to look at adding bits such as max-height and max-width. OTOH, since you appear to be using full page images with your splitting before and after, you may want to look at using an svg wrapper.

As for someone who is professional or knows editing epubs? I think you just insulted one of them.

BTW, page-break-before and page-break-after are replaced by break-before and break-after.