Range of secular variations of e_b and i_mut from numerical simulations iterated for i_c and Ω_c. Panels a and b were obtained from the model for which the GR and tidal effects were accounted. The values of those variations, Δe_b and Δi_mut, are coded with a colour scale. The horizontal dotted and dashed lines show the 1 and 2 σ ranges of i_c constrained from the astrometric observations. The values of i_mut between the Kozai’s angles are located outside the ovals marked with light grey continuous lines. Panels c and d show the same parameters but for the Newtonian-only model. The simulations leading to unphysical orbits are plotted in greyscale, and those for which we observed orbit flipping from prograde to retrograde or vice versa are marked in green.