Joint RM+RV analysis of all available RV values for HD 332231, excluding the last 4 out of transit points of CARMENES 18-10 observations shown as red points. (a) Joint analysis of previously obtained RV data from spectrographs at Keck (HIRES) and Lick (APF) observatories (Dalba et al. 2020), together with the data obtained with CARMENES. (b) Same data phase-folded for our derived system parameters from the fit above. (c) Zoom into the epoch of CARMENES observations (including the planetary transit) and the fitted RM function to the data. The thin grey lines are 300 random realisations drawn from 1σ regions of the posteriors. The lime dashed line represents the best fit model when λ is fixed to zero, performed for the purpose of robustness estimation. The residuals of this model are omitted for clarity.