Trouble exporting my Publisher layout to printable PDF

[PhilBJ]

I have a large Layout (ca. 1000x650mm) I built with a target resolution of 300 DPI. When I export it to PDF with the default export settings(PDF1.7) I get a crisp output and everything is as detailed as I want it to be. Now my customer want it to have as PDF/X4 or PDF/X1 format. Whenever I try to export it in one of these formats without changing the other default settings, parts of my layout(especially the ones i imported from other pdfs) have a terrible grade of detail. The layout elements I made with Publisher seem to be fine though.

Can some one hinte me in the right direction?🧐

[PhilBJ]

I could solve the problem: The IMPORTED PDF causing the trouble was a PDF 1.4. So Affinity could export the layout to PDF 1.x  without problems. But as soon as I switched the export settings to PDF/X-1-4 it just exported Affinitys bitmap preview of the PDF. Now here is the solution: I did not even change the input PDF's version but changed affinitys settings for pdf-transfer from transfer to interpret. Now I have a perfect result.

Cheers :)