I received notifications when host went back to up state, but it’s services were still critical.
When no checks are running if the host is down, then in the time it’s back up, there is still time at least to one check on services (because they are in soft state) and they get ok.
If the check are done during the host down state, when the host is back up, all services are already in hard state and notifications are sent immediately.
I found this solution here
It’s not the problem. In this situation the host interconnect remains up, even the ping service is critical, because it’s still reachable - host reachability RTA values (C,W) 100.00 ms, 200.00 ms vs ping service 3.00 s, 5.00 s