Phase-covariant mixtures of non-unital qubit maps

We analyze convex combinations of non-unital qubit maps that are phase-covariant. In particular, we consider the behavior combine amplitude damping, inverse and pure dephasing. show mixing channels can result in restoring unitality, whereas commutative lead to non-commutativity. For Markovian semigroups, prove classical uncertainties cannot break quantum Markovianity. Moreover, contrary Pauli channel case, semigroup be recovered only by two other semigroups.