Posterior distributions of the recovered GWB from injections on synthetic data mimicking DR2new. Top panel: statistical offset in an ideal dataset. The square marks the injected value and the blue contours are 1σ and 2σ of the recovered posterior. Bottom panel: effect of high-frequency noise mismodeling on the recovery. The orange, blue and green contours are respectively obtained when EFAC = 0.8, 1, 1.2 are used for the recovery (injected EFAC = 1).