Four Keplerian best-fit models including all signals (periods of 9.4, 13.9, 18.9, and 19.1 d; top panel), the three signals connected to the stellar rotation (9.4, 18.9, and 19.1 d; middle panel), and the two signals around 19 d (bottom panel), resulting in the amplitude variation following the beat frequency of 2042 d in the observed time span. The red dots are the HARPS-N S2 to S6 and CARMENES data points.