I see.
Topic subject and first post said that PDFs would be different on Linux than on Windows which was surprsing.
So it is just different programs generating PDFs differently, which is much more likely given they will often use vendor specific code to do that.
Which also makes it very difficult to check what is actually different.
Aren’t such tools just generating PDFs?
I’ve worked with Scribus for many years (for brochures and such) and always used its PDF to send the content to the printing company.