I didn't watch the Villa vs Sheffield Utd game but did see the replays of the goal that never was.

Does anybody know why VAR didn't intervene? I realise that this isn't something that normally falls under the remit of VAR since the Hawk-Eye goal line technology is usually so reliable. But this was so blatant and VAR usually spends ages agonising whether a toe nail was off-side so it is surprising.