We prove that Novodvorsky's definition of local L-factors for generic representations of GSp(4) x GL(2) is compatible with the local Langlands correspondence when the GL(2) representation is non-supercuspidal. We also give an interpretation in terms of Langlands parameters of the "exceptional" poles of the GSp(4) x GL(2) L-factor, and of the "subregular" poles of
GSp(4) L-factors studied in recent work of Rosner and Weissauer; and deduce consequences for Gan-Gross-Prasad type branching laws, either for reducible generic representations, or for irreducible but non-generic representations.

The author gratefully acknowledges the support of the Royal Society (University Research Fellowship "L-functions and Iwasawa theory") and the European Research Council through the Horizon 2020 Excellent Science programme (Consolidator Grant "Shimura varieties and the BSD conjecture", grant ID 101001051).