After reading your post I did some tests. I still have my old (and slow) Imac 2011 2,5 GHz Intel Core i5. I have affinity publisher 1.10.4 running on this Imac.
Guess what? The same documents PDF's for print are tuning out the way they should on this old imac! No weird croppings or corrupted images here!
My new macbook pro: Apple chip M1, OS Monterey 12.6 and Affinity publisher 1.10.5.
No PDF's for high quality prints turn out the way they should on the new macbook, there are weird croppings or corrupted images (like yours) in those PDF's. (The documents are the same I tried on the old imac.)
So, I think we now know the problem! It has got something to do with the new apple chip/OS Monterey and Affinity publisher 1.10.5.
I would love to get an update, would even pay for it! I hope to hear from the company when we can expect this update?🙏
See screenprint images (same document) for the white cropping in my pdf. It is not in the pdf from the old imac, only in the new one.
Are I and @Kiwibonds the only ones having this problem?