I have no answer to your question, however I have noticed that browers treat PDF output from Tiki (Chrome and Firefox namely) differently and that’s related. 🤗
One thing is sure for me about printing a PDF from Tiki;
Tiki + Browser + OS (?) = too many ways to do the same thing and users are confused.
To avoid this I usually set a "Print PDF" button that do what it says.
We should evaluate, simplify and keep only ONE good working way.