[darktable-user] Exif tag lost during conversion nef to jpg

Hi, while converting from nef to jpg using     darktable-cli file.nef xmp-file file.jpg the exif tag GPSAltitude is lost. There are more differences in the exif tags between the jpg and nef file. See attached pdf. I seems to me  the missing GPSAltitude and the double DateTimeOriginal are

[darktable-user] advice asked

in yyy.xmp . However, there are so many possibilities and conditions (night, fog, rain, snow, sun to name a few) that I wonder if this is the right way. Is there anyone who has experience with something similar and/or can assess my method ? -- Cordialement, Ruud Baart