Strange PDF behaviour export PDF

Hi,

Apologies for my abscence, many deadlines, but here is how it evolved so far.

In Indesign CC 2021, it all seems OK. A Preflight run didn't find anything unusual, nor in the buttons or anywhere else. No tranparancy or anything that could suggest a weird setting in Indesign was discovered.

What I suggested, and what solved the problem ... for now, ... was to resave the preset for that PDF export. I simply resaved the same PDF export preset but with a different name (e.g. with a v2 behind the name) in the Indesign export Adobe Print PDF dialog (cmd+e). So far, we haven't had the issue anymore, but it can always pop up again. In that case, the problem must obviously, be somewhere else and I will try to provide screenshots.

Personally I had to work for that customer the past 2 weeks (I usually never do) and haven't experienced the problem myself, as the PDF export presets are stored locally on the Macintosh HD my intuition got stronger the problem is/was PDF preset related.

So the way I see it, is that the PDF preset, which my collegue uses for some years now, might have encountered a glitch, due to an Indesign update or for some obscure mysterious reason.

Well yes, the term "button" is not in the sense of interactive ones, my bad. The PDF exports are for print. It seems like on some objects, the red rectangle with white text in it, gets set on "no color" as fill color when exporting to a print PDF. The odd thing is, while all these objects are duplicates, it doesnt happen on all off them. One day it works fine, on other days it randomly flushes the fill color to "none" in the PDF for a few objects. In Indesign, the red color is still visible. Turning on "overprint preview" should not result in a solid red color, to be totally disappear right, or convert the swatch to 0%? I should test with the PreFlight module perhaps.