Unexpected Lines Appearing in PDF Export from InDesign - Not Present in JPEG Export

[eidola_editions6410]

when I export my file to PDF lines appear. They do not correspond to real blocks on indesign.
When I make an export text in jpeg these lines do not appear.
How to fix the problem of exporting to PDF?

<Title renamed by MOD>

[Willi Adelberger]

Export without transparency flattening. Export as PDF/X-4 and use, if you place files, files without transparency flattening. Avoid PDF/X-1a or X-3, avoid EPS and Postscript, avoid printing PDFS.

[Robert at ID-Tasker]

@eidola_editions6410

What if you zoom in - to the max?