  We calculate the cross section of diffractive dijet photoproduction in $ep$
scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we
supplement by a model of factorization breaking for the resolved-photon
contribution. In this model, the suppression depends on the flavor and momentum
fraction of the partons in the photon. We show that within experimental and
theoretical uncertainties, the resulting approach provides a good description
of the available HERA data in most of the bins. Hence, taken together with the
observation that NLO pQCD explains well the data on diffractive photoproduction
of open charm in $ep$ scattering, our model of factorization breaking presents
a viable alternative to the scheme based on the global suppression factor.
