I've been having a sporadic issue with our 3CX VoIP server. Occasionally, we will get dropped incoming calls. I've been running wireshark across the interface and I'm seeing a ICMP Destination Unreachable, Port Unreachable. This is for WAN To LAN, LAN to WAN, and LAN to LAN. The one consistency is that it always involves the IP address of our 3CX server as either the source or destination. This only started happening once we switched out routers. The system is running on Windows 2016 Datacenter in a Hyper-V environment.