MWL light curves between MJD 57720 and MJD 57918. From top to bottom: MAGIC (0.2–1 TeV & > 1 TeV) and FACT (> 0.95 TeV), Fermi-LAT (0.2–2 GeV & 2–300 GeV), Swift-BAT (15–50 keV), NuSTAR and Swift-XRT (3–7 keV & 7–30 keV), Swift-XRT (0.3–2 keV & 2–10 keV), UV-optical (Swift-UVW1/UVM2/UVW2 & R-band), OVRO (15 GHz), Metsähovi (37 GHz) and Medicina (8 GHz and 24 GHz). The dotted blue horizontal line in the first two panels from the top shows the 1 C.U. flux in the > 1 TeV & 0.2–1 TeV bands, respectively. The Fermi-LAT data have a 3-day binning. The Swift-BAT light curve is computed in 3-day and 6-day binnings, as well as 1-day binning around the flare. The vertical black dashed lines highlight the dates that show an enhanced VHE activity and appear as outliers in the VHE versus X-ray correlation plots (see Sect. 4).