Comparison of the $\pT$-differential $v_2^{\rm \mu} \lbrace {\rm 2PC} \rbrace$ of inclusive muons at forward (left) and backward (right) rapidities in high-multiplicity p--Pb collisions at $\sNN =$ 8.16 TeV with AMPT calculations . The predictions are shown for muons from charm-hadron decays and beauty-hadron decays, separately, muons from charged-pion and kaon decays, and for muons from the combination of the various sources. The contribution of muons from both charm- and beauty-hadron decays is also displayed.