Evolution of the interstellar absorption N_H (panel a), the plasma temperature kT (panel b), the input photon temperature T₀ (panel c), the plasma optical depth τ_p (panel d), and the reduced χ² of the fits (panel e) as a function of the 1–30 keV flux obtained from the Insight-HXMT spectra using the TBABS × (GAU+CUTOFFPL × GABS) model. Red and blue dots show the same parameters derived from two single NuSTAR observations and two combined observations (NuSTAR+Insight-HXMT), respectively.