Evolution of spectral parameters and optical–to–X-ray fluxes. From top to bottom: Intrinsic flux in the 0.3–10.0 keV band, photon index, curvature parameter, energy of the SED synchrotron peak and associated flux, and UV (W1, M2 and W2 filters) and optical (V, B and U filters, as well as the VT R and B band) fluxes. The dashed blue line in the β panel represents β = 0.4, considered a threshold value between low and high curvature. The red stars represent unconstrained points whereas red triangle represent 1σ upper limits. The blue and magenta backgrounds highlight periods 1 and 2 respectively.