Chaos map around our best-fit solution. The map has a resolution of 121 × 121 pixels, which represent as many system configurations that were numerically integrated to derive a NAFF chaos estimation as defined in Eq. (1). We report the results in the form of a color code, where the bluer regions of the map refer to systems with smaller NAFF, and hence weaker chaos. The nearby principal MMR are indicated, and the vertical line marks the orbital period of planet c as estimated from our global fit.