Three upper subpanels (A)–(C): folded Fermi gamma-ray profiles in the three MJD ranges with error bars for the 1σ uncertainty: (A) for MJD ∈(54684, 56858), (B) for MJD ∈(56858, 59031), and (C) for MJD ∈(59031, 61205). Compared with the profile in subpanel (C) with embedded FAST observation duration, the earlier MJD profiles are wider, implying uncorrected periodic perturbations from an imperfect ephemeris of this triple system. Three lower subpanels (D)–(F): temporal power spectra for the pulsar spin-phase data of Fermi gamma-ray photons in the three MJD ranges. Some uncorrected perturbations of the inner orbit from the tertiary in the timing model could induce some power at the exact frequency for the inner orbital period, as we do see in subpanel (D) for the early MJD range.