I have exactly the same problem using a HP7740 and connected to a Mac over a wireless network. There are a few things which have worked for me.
1 - in desperation, rather than save the file I would print to PDF (part of the Mac OS)
2 - In the auto enhancements page (inside the HP Smart App), I turned off rotate images
Both of the above allowed me to get a full PDF document which I could then work on using the Mac preview software (manual rotation etc). Not sure if you are using a Mac, but perhaps the above would at least let you get a file saved with all the pages scanned (possibly upside down).
As for the advice to remove and install the software, tried that a bunch of times and it did not work.
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