I managed to find the PDF in question. If posting it here is wrong please do let me know or edit it out
https://alldrink.de/wp-content/themes/alldrink/assets/angebote/pdf/08_04_20_04_2019_AB.pdf
My guess is that whatever you are using to make the PDF is leaving out specific information that macOS/iOS needs. PDF is a native file on macOS/iOS (NextStep used Display Postscript and the first iterations of OSX used PDF as a native display rendering engine. Hopefully my info is not badly out of date.)
But the macOS/iOS PDF rendering engine may be based on a PDF standard that is incomplete or does not support everything that Ghostscript outputs. Not being really familiar with Ghostscript I don't know.
It works in Acrobat on a Mac but not in Preview and displays that issue on my iPhone. Both devices have the latest OS versions.
If it is possible in Ghostscript to target earlier versions of the PDF standard when you output your brochure, I would try that. Possibly with multiple earlier versions till you hit one that renders on Apple OS systems better.
The other possibility is that the fonts (or graphics) used in the the non-rendering boxes are not downloaded to the PDF by Ghostscript. Perhaps if you render the graphics in the source as high res bitmaps (if they are not already) rather than vector images/postscript fonts that could be it as well.
You might also try asking this question on a discussion board that deals specifically with pre-press output to PDF as I would bet they would take one look at this and know what the problem is.
Sorry to be so vague, this started as a comment but I realized it was too long, but may not be an actual answer. Hopefully it points you to an avenue that leads to an answer...