Notification and lockdown happens the following day

When my son reaches his 1 hour limit and his PC is locked, I don't receive the notification on that day. I receive it on the next day when he tries to login again and his PC is locked again when it shouldn't so, he has to re-login and everything is fine. I should receive the notification at the time his PC is locked and not on the next day and his PC shouldn't lock the next day due to yesterdays restriction.