  We compare the massive Kalb-Ramond and Proca fields with a quartic
self-interaction and show that the same strong coupling scale is present in
both theories. In the Proca theory, the longitudinal mode enters the strongly
coupled regime beyond this scale, while the two transverse modes propagate
further and survive in the massless limit. In contrast, in case of the massive
Kalb-Ramond field, the two transverse modes become strongly coupled beyond the
Vainshtein scale, while the pseudo-scalar mode remains in the weak coupling
regime and survives in the massless limit. This indicates a contradiction with
the numerous claims in the literature that these theories are dual to each
other.
