Anomalous differences in semi-major axis between the Gaia orbital solution and the JPL orbits. The plot shows the relative difference as a function of the Gaia formal uncertainty σ_a/a for all solutions with |∆a/a| > 1 × 10⁻⁷. The left group (σ_a/a < 5 × 10⁻⁸) is just the small statistical right tail of the distribution of Fig. 20 and is determined by the selection threshold for the plot. The group on the right with σ_a/a > 1 × 10⁻⁷ comprises solutions with a poor fit performance and is not an issue: these orbits could have been filtered out in the pipeline and were excluded from the delivery.