GLS periodograms of the OVRO 15 GHz data. (a) Periodogram of the entire light curve shown in Fig. 2 (cf. Jaron et al. 2024). (b) Zoom onto the region around the orbital period. A distinct two-peaked profile is present. The vertical dashed line marks the position of P₃, as reported by Zhang (2024). A significant feature is indeed detected at this position. (c) Periodogram of interval I (green-shaded area in Fig. 2). The only significant feature is at approximately the orbital period. (d) Zoom. There is only one peak. (e) Periodogram of interval II (yellow-shaded area in Fig. 2). The only significant feature is at approximately the orbital period. (f) Zooming in on the orbital range reveals a two-peaked profile.