@agrigio I had the same problem as in the Thidigikam-image-orientation-when-exporting thread. It happened on a recent Windows build of both programs, when using Digikam to geotag my images, the tiff:orientation="8" tag was added to the xmp sidecars, and when esporting to jpg from ART, the jpg inherited from this tag, making them wrongly rotated (both the Windows file explorer and XNViewMP show the jpg’s with a wrong rotation). I had to use a batch script to remove the culprit line in the xmp sidecars before exporting to jpg to have ART produce files with the right orientation.
I don’t know which part is behaving bad, probably either exiv2 or digikam? Or is it up to the raw converter to make sure the tiff:orientation="8" line is not read and used to set the jpg orientation?