Does anyone know what is the reason for the e4's sending UDP packets  to port 0 to a number of hosts on the internet? The following traffic is logged by my router.

list FW-VLAN10-IN denied udp 192.168.0.246(0) -> TARGET(0)

The whois entry added to some of the TARGETs:

 -> 103.106.65.219, LOCALHOST-NZ-CLIENTS-ERAYD
 -> 108.128.150.188, Amazon
 -> 128.138.140.44, University of Colorado (UNIVER-24)
 -> 129.6.15.28, National Institute of Standards and Technology (NIST)
 -> 129.6.15.29
 -> 131.107.13.100, Microsoft
 -> 132.163.97.6, National Institute of Standards and Technology (NIST-1)
 -> 162.159.200.123, Cloudflare, Inc. (CLOUD14)
 -> 192.36.144.22, D-GIX Service network
 -> 34.241.249.137, Amazon
 -> 34.242.63.170, Amazon
 -> 34.242.88.33, Amazon
 -> 34.246.123.249, Amazon
 -> 34.255.40.166, Amazon
 -> 52.17.157.95, Amazon

Edit 1: Looks like most of these are NTP servers, which means that the e4 doesn't honor the NTP server offered by DHCP.

Edit 2: These are NTP servers, permit udp port 123 any fixed it.