Phase-folded light curves of the M9 RRL sample, based on Gaia epoch photometry and variability periods. Red, green, and blue points correspond to G_RP, G, and G_BP passbands, respectively. Note that for V2 and V10, the phase coverage of the red and blue bands is very poor, while for V2, V10, V18, and V19, the G_BP data are very close to or above the G-band points. In both cases, they lead to incorrect estimates of the mean magnitude.