  We discuss two models which are part of a class providing a common
explanation for lepton flavor universality violation in $b \to s l^+ l^- $
decays, the dark matter (DM) problem and the muon $(g-2)$ anomaly. The $B$
meson decays and the muon $(g-2)$ anomalies are explained by additional
one-loop diagrams with DM candidates. The models have one extra fermion field
and two extra scalar fields relative to the Standard Model (SM). The $SU(3)$
quantum numbers are fixed by the interaction with the SM fermions in a new
Yukawa Lagrangian that connects the dark and the visible sectors. We compare
two models, one where the fermion is a singlet and the scalars are doublets
under $SU(2)_L$ and another one where the fermion is a doublet and the scalars
are singlets under $SU(2)_L$. We conclude that both models can explain all new
physics phenomena simultaneously, while satisfying all other flavor and DM
constraints. However, there are crucial differences between how the DM
constraints affect the two models leading to a noticeable difference in the
allowed DM mass range.
