Thanks @BrightSilence, I just want to be sure of what is happening before I comment or do anything about this.
My quick guess is that the payout is probably still calculating using the tb*h… So it’s probably getting the total disk space used this month and dividing by (24*30) instead of just 30:
29.89TB*d / 30 = 996.33GBm
29.89TB*d / (24 * 30) = 41.51GBm (which reflects the wrong value on the payout info)