Distribution of BXAF_{0.5 − 7 keV} fluxes for the eRASS 1 (in blue) and Chandra observations (red) of J202040−621509. The vertical black lines show the locations of the 15.9-th and 84.1-th percentiles of the distributions. The green and pink regions span the 2.3-th and 97.7-th percentiles of the distributions. The lower panel shows the time separation in days between the two observations. We measured a decrease in the source flux between the two epochs significant at the ∼2σ level.