A case for the German administrators of the site:
The "Steinfeld Steingrab 2" is most likely a passage grave and not a chambered tomb. The relevant literature from the offical responsible archologist Dr. Tempel describes the large stone grave as a possible passage grave. The term "chambered tomb" is nowhere mentioned.
You can check this information here:
Tempel, Wolf-Dieter (1999): Auf ur- und frühgeschichtlichen Spuren durch den Landkreis Rotenburg, Wegweiser zur Vor- und Frühgeschichte Niedersachsen - Heft 22, Oldenburg p. 38-40
Or on the Wikipedia page:
https://de.wikipedia.org/wiki/Großsteingräber_bei_Steinfeld_(Bülstedt)
Something is not right. This message is just to keep things from messing up down the road