You noted trying each of these settings:
- Flip on long/short edge
- Portrait/Landscape
However, you didn't mention which combination therein you tried.
The reason I mention this is because I'm picturing say for example a calendar; if you're in Landscape & Flip on Long edge; then the normal / expected result would be that the back page is printed upside-down relative to the front page.
This is because, when you flip to the next page of the 'calendar', the upside-down page would now be right-side up by the change in position.
The same would hold true, for Portrait & Flip on Short Edge as well; because if it's in portrait and the flip is at the top you'd assume the same sort of change in position.
If it still didn't work after trying either of these two scenarios:
- Flip on long & Portrait
- Flip on short & Landscape
Then I would strongly suspect the cause is a bug. In that case, you should check if there are any updated drivers for the printer, which I think you'd find here: http://support.hp.com/us-en/product/HP-Photosmart-5520-e-All-in-One-Printer-series/5157533/model/5157535/drivers/
And check Windows update in case the issue is the fault of Word. You might have to check the 'optional' updates as well as the 'important' updates to be through.