P–P plot for the GWB-amplitude recovery for the LoudGWB_set of simulations. The dashed line refers to the inference runs where all the intrinsic noise parameters are fixed in a noise dictionary and the amplitude of the GWB is the only free parameter. The solid line is the result of MCMC runs over all 62 noise parameters. The theoretical expectation for an unbiased recovery and the predicted variance of one- and three- σ are represented in different shades of blue.