Multi-band time series and evolution of optical and radio parameters (including data presented by Baglio et al. 2024). Error bars represent the 1σ confidence levels. In the seventh and eighth panels, horizontal dashed red lines mark the average optical polarisation degree (P_opt) and angle (PA_opt), with shaded areas indicating one standard deviation about the mean. In the ninth panel, a horizontal dotted line shows a spectral index of 0 (i.e., a flat spectrum). In the final panel, downward arrows denote 3σ upper limits on the radio polarisation degree (P_radio). TDB stands for barycentric dynamical time.