  In this note, we show that there exist solutions of the Muskat problem which
shift stability regimes in the following sense: they start stable, then become
unstable, and finally return back to the stable regime. This proves existence
of double stability shifting in the direction opposite to the one shown in
[C\'ordoba, G\'omez-Serrano, Zlato\v{s}, A note on stability shifting for the
Muskat problem. Phil. Trans. Roy. Soc. A, 373 (20140278), 2015]
