Yet you claim they tested one in 1944

Hmmm

Yes,Ruegen test apparently took place in late 44,but information about that
very sketchy,but there is even a photo of it taken from stralsund,I did not
know anything about that before.
Much publicized test took place on 4.3.45 in Ohrendorf TUP.
Germans apparently built a w54 style low yield bomb (15-20 t yield range)for
testing purposes only.