I have a problem with exporting to PDF. If I choose File > Export and then the preset "PDF (for print)", there is always + 0.01 cm at the width and height (for example 14.8 x 21.0 cm becomes 14.81 x 21.01 cm). This also brings a small white stripe at the right side of the document.
If I open the document with Affinity Designer and then choose the Export Persona, the document size is correct. Unfortunately there is no Export Persona in Affinity Publisher, so I always have to open Affinity Designer. By the way: It happes in Affinity Designer as well, if you choose File > Export.
I'm pretty sure, that this is not a real problem because I cannot imagine, that this is visible after printing. But I just wanted to mention it.