I've been having problems lately printing booklets. Using double sided printing I have to specify whether to flip long or short side. Logic suggests to me that printing, say, an A5 booklet on A4 sheets, I should specify "flip short side". However that would print alternate sides upside down, so I'd always called for "flip long side" and its been fine.

Lately however, the latter setting was giving me upside down pages, so I've been specifying "flip short side" and the printing has been OK.

Today, "flip short side" gave me upside down pages, so I had to use "flip long side" setting again. Very puzzling!

Something unusual then happened: I had a thought! Today I had reverted to using my older Win 10 Laptop, whereas lately (as in two paragraphs back) I had been using my newish Win 11 laptop. So I tried the same print job on my newer laptop, and "flip short side" was OK.

Therefore, using the same program (PagePlus X9, of course) and the same printer (HP OfficeJet Pro 8710) with different laptops, gives me a different flipping result!

Is it caused by the different operating systems (Win 10 and 11), or what?