Time evolution of the A/B, A/C, and C/B flux ratios as measured by ALMA, compared to the optical (COSMOGRAIL) and X-ray (Chandra) monitoring. We also show the average value of the R-band flux ratio (dashed line) and predicted value from the Suyu et al. (2013) lens model (dotted line). The amplitude of ALMA A/B flux ratio variations is comparable to that at optical and X-ray wavelengths but shifted in time, indicating different sizes or a spatial offset between the three components.