Cross-correlation of optical/UV vs X-ray. The five rows of the plot are the five states (A, B, C, D, E) defined in Fig. 1. Horizontal red and blue dashed lines are 2σ and 3σ significance respectively. We do not observe any significant time lag in any of the combinations. During state C, we see some time lags but the correlation coefficient are below 50% and below 2σ significance, and hence do not consider as an actual time lag.