pdf download missing images

[emma1997]

When the "Meditations on Breguet and Mathematics" pdf is downloaded to my iPad (from Breguet Self-Winding Watches ) some of the figures in it are not displayed, and there is blank space where the figures should have been. However, it downloaded correctly on a laptop.

More bizarre: First using my iPad, I put the pdf on iCloud and then opened it on my desktop - the figures were still missing. Second, I emailed the pdf from my iPad to myself and opened the email attachment on my desktop - all the figures appeared correctly!

I have no idea why! Any suggestions?

[emma1997]

After some tedious work I am confident that the problem is within iOS 12 and it does not render CMYK images. Grey or RGB images are fine.

Is there any way of contacting Apple about this?