Observed minus calculated diagrams of the transit times of the five planets of the HD 108236 system, obtained by using the ephemeris of the global fit or the updated T₀ values reported in Table 5. Transit times were obtained from the individual analysis of the transits (see Sect. 4). Blue and orange symbols correspond, respectively, to TESS and CHEOPS observations. The gray regions represent the ±1–2σ uncertainties of the ephemeris equations. Vertical dashed lines mark overlapped transits in the light curves.