Duplex / Double-sided scanning produces up-side down back pages
For my document workflow (unchanged since several years with the same combination of scanner, driver and scan software) I will scan letters with the option "All Pages From Feeder" and the preference "Scan Sides" set to "Both" and save them to a PDF. So far, all pages were shown right-side up in Documents Scanner's preview window and saved properly.
Since version 40.1, the resulting scan shows each back side of a sheet up-side down (rotated by 180 degrees). When scanning several sheets of paper, I now have to rotate every other page by 180 degrees before saving.
My scanner is an Epson Stylus Office BX635FWD. The scanner has a duplex scan unit that flips each page after scanning the front to scan the back, i.e. each page is passed through twice. Its driver is unchanged since May 2018.
Debug log: simple-scan.log