Pulsed fraction spectra (see Sect. 5) of the three NuSTAR observations of MAXI J0655 taken during the 2022 outburst (ObsID 80801347002 and 90801321001), and in 2024 during the low-luminosity regime (ObsID 31001020002). Upper panels show data and a best-fitting polynomial fit. Lower panels show residuals in units of sigma with respect to the best fitting model. Note for the ObsID 80801347002 the presence of an additional Gaussian absorption line at ∼6.2 keV. For the other two observations the fit linear slope is consistent with zero at the 2σ c.l.