OCR highlights are flipped in both directions on each page

[GaryT-NZ]

The yellow (and green) OCR highlights for searched text are incorrectly positioned - they appear to be flipped both horizontally and vertically on each page

I have a pdf of an old manual that is just scanned, so has no text search - I set up OCR in naps2 and saved it.
I opened it in various pdf readers, and although the text is now searchable, the highlights are all incorrectly positioned, and therefore make it still difficult to find the text. I realised they appear to be flipped on the page. I extracted the highlights by screen capturing and filtering, and overlaid the flipped highlights, and they then appeared correct.

As the file appears when searching for 'adjust' (in Edge):

extracted higlights, flipped horizontally and vertically:

And manually overlaid on the pdf file in Inkscape:

If it helps I can either upload the (large) files, or see if I can pull out one page that demonstrates the issue

[digidigital]

The issue might be that the scanner saves the image in a rotated state and instructs the viewer to display it upright. Or something similar.. Scanners sometimes do strange things and it's hard to detect the correct Image orientation when you have to put an overlay on the page. One solution is to render the PDF Pages in the final position AS Image with the same DPI and put the overlay on the rendered page not the original PDF (at least if there is some rotation or matrix operation on the page or image)