GLS periodograms of: (a) RVs from CARMENES VIS and the respective spectral window function (gray), (b) RV residualsafter subtracting the one-planet signal, (c) RV residualsafter subtracting the two-planet signal, (d) RV residualsafter subtracting the one-planet signal plus GP, (e) RV residualsafter subtracting the two-planet signal plus GP, (f-l) CRX, dLW, Hα, Ca IRTa (“a” corresponds to the Ca II λ8498.0 Å line), TiO7050, TiO8430, and TiO8860 activity indices from CARMENES VIS data. The “cp” in the residual models (panels a–e) corresponds to circular orbits (for a detailed explanation, see Sect. 4.3). In all panels the vertical lines indicate the periods of 0.67 d (red, USP) and ~ 9 d (green, second planet candidate). The rotational period of the star (blue line) falls in the region between ~ 19 and 26 d. The horizontal lines mark the theoretical FAP levels of 1% (dotted), 5% (dash-dotted), and 10% (dashed).