As Fig. 2, but now zooming into the critical 2018 pericentre residuals (best-fit f_SP = 1.1 minus f_SP = 0, with all other parameters fixed). Bottom two and top right panels: blue filled, open black circles (with 1σ uncertainties) are averages of GRAVITY data. The grey bar on the left denotes the constraints obtained from NACO imagery of S2 and Sgr A* flares on the location of the apocentre value (2010.35). Averages (and 1σ uncertainties) of the radial velocity residuals from SINFONI are open black, blue filled circles (top left). The residuals of the best-fitting f_SP = 1.1 minus f_SP = 0 curves are plotted in red.