DRP evolution with X-ray (left) and optical (right) fluxes for the four outbursts of J1357. The X-ray flux for each DRP was interpolated between those of the closest X-ray observations (0–3 days). The 2017, 2019 and 2021 LT data sets only include epochs with significant peaks in the LSPs (see Figs. 5, 6 and B.1). Open markers (epochs #2, #5 and #6 of 2021) indicate the DRPs corresponding to the LSP peaks with the highest power (Sect. 3.3.1). The grey band indicates an optical magnitude interval (17.1–17.3) with a peculiar DRP evolution (also marked in Fig. 2, see Sect. 4.2.1).