The dialog box shows the correct settings for duplex printing but it only prints each page on one side. I have tested the same document using OnlyOffice and it works fine. So, I assume the problem is with LibreOffice settings. Yes?
Yes, you seem to assume this.
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But as I used duplex printing with LibreOffice over years, it seems to be possible. Maybe there is more to this topic than you assume.
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As you didn’t gave any details it is hard to give you suggestions (except for the blind shot “try safe mode”). So I can only wish you good luck …
If you are printing more than one copy of the document when the error occurs, you could see if ticking the box Create separate print jobs for collated output helps.
try this classical : Safe Mode
if still not ok, please provide #More_details → Ask/Guide - How to use the Ask site - The Document Foundation Wiki