Overview of the sodium doublet transmission spectra used in this work, normalised to 0 with the added contribution of the obscure disk of the planet. The disk contribution depends on the white-light radius and is therefore only a best-effort approximation for the real continuum in the order of the sodium doublet. Because the same radius is also used for the retrieval, this has no effect on our conclusions. Top panel: HARPS spectrum from Seidel et al. (2019) reprocessed with the updatedsystem parameters. Centre panels: ESPRESSO spectrum for each night. Bottom panel: all three datasets combined. The line centres of the sodium lines are indicated as dashed vertical blue lines, and the line spread function of the respective instrument is shown as a blue graph.