  In six- and seven-dimensional gauged supergravity, each scalar potential has
one supersymmetric and one non-supersymmetric fixed points. The
non-supersymmetric $AdS_7$ fixed point is perturbatively unstable. On the other
hand, the non-supersymmetric $AdS_6$ fixed point is known to be perturbatively
stable. In this note we examine the newly proposed non-perturbative decay
channel, called brane-jet instabilities of the $AdS_6$ and $AdS_7$ vacua. We
find that when they are uplifted to massive type IIA and eleven-dimensional
supergravity, respectively, the non-supersymmetric $AdS_6$ and $AdS_7$ vacua
are both brane-jet unstable, in fond of the weak gravity conjecture.
