My HTTPD accesses Comodo US by UDP

I run a home server using Apache, together with Comodo CIS as a firewall. Comodo log of last night says that Apache accessed Comodo USA ( by UDP and asked if I allow it. I could not respond because it was midnight.
Now, what is this access for? Can I just keep this UDP access blocked?
I have not seen this access for years.
May I have any guru’s help here?

It’s not something to worry about. Port 4447 UDP is part of the Comodo Cloud look up. It sometimes happens that it responds slowly breaking the stateful inspection mechanism of Comodo firewall. So, CIS no longer sees the traffic as a reply to outgoing traffic from your computer (the cloud look up) and will register it as unsolicited incoming traffic. You’re not in danger.

The UPD protocol is a stateless protocol meaning that it does not maintain a connection.

Thanks, Eric.
Good explanation.