Generalised Lomb-Scargle periodograms for RVs of LTT 3780 (a), their residuals (b) after fitting a sinusoid with period and phase corresponding to the transiting planet TOI-732.02 (f_c = 0.081 ± 0.002 d⁻¹, P_c = 12.3 ± 0.3 d), marked in red, and their residuals (c) after fitting two sinusoids with periods and phases corresponding to the transiting planets TOI-732.02 and TOI-732.01 (f_b = 1.298 ± 0.002 d⁻¹, P_b = 0.770 ± 0.001 d), marked in blue. Panels d–i: periodograms of the chromatic index, differential line width, Hα index, cross-correlation function FWHM, bisector velocity span, and contrast, all of them derived only from CARMENES observations. Horizontal lines show the theoretical FAP levels of 10% (short-dashed line), 1% (long-dashed line), and 0.1% (dot-dashed line) for each panel.