embedded images in pdf not rendering in native Apple apps any more

Hi,

Native rendering of pdfs in MacOS seems to have become seriously buggy.

I have a large number of pdf documents (and keynote presentations containing copy-pasted parts of these pdf documents) that have embedded bitmap files in them. These used to render just fine. However, I have noticed for some time now (~1 year?) that with newer MacOS versions, none of the native Apple apps (Preview, Keynote, Safari, Pages) render these correctly any more, and simply show a blank space where these images should be. I could just stop using Preview for opening the pdf files -- but what do I do with all my Keynote presentations that have the same issue now?

Thank you.