You haven’t said when you made the decision to end HB from May 2020. I’m assuming some time later, and in the meantime HB had been paid all along through 2021, 2022 … maybe even early this year. But at some point, it has come to light that a period of absence in excess of 52 weeks occurred between 2019 and 2020.
From 1/8/2020 the claimant was never absent from home for longer than 52 weeks, so the only overpayment there can be in this case runs from the point at which it would have first appeared (without the benefit of hindsight) that the original absence was likely to substantially exceed 52 weeks. That could have been as recently as May 2020, maybe a bit earlier. This is a textbook closed period supersession: you remove entitlement for the overpayment period, from ??? 2020 to August 2020, and leave the ongoing award undisturbed after the end of that closed period.
It’s not a case of underlying entitlement: it’s a case of identifying a period in which there was no entitlement at all, and periods in which the claimant was fully entitled to the amount paid – textbook CPS as I say.
