I also have the Klagenfurt Hs126s noted as Nahaufklärungsstaffel Kroatien. I believe a description of the most reproduced photo in the Luftwaffe Verband first made the assertion of the 9H unit code being applied, but I’ve never seen one.
BTW at least another 4 identically marked (at least in terms of Luftflotte 4 ID markings) were photographed at Bad Aibling (and seen/found on Marc’s excellent Flickr page):
https://www.flickr.com/photos/280920...7631640861826/
Cheers,
Chris