Thank you so much for providing this information. Ever since Xfinity did their infrastructure upgrade in my area I would have intermittent connectivity with one of my WAN's. Currently, I am running two WANS (both Xfinity) and have them in a load balance configuration. When I initially set this up in Pfsense everything was working fine. After the Xfinity upgrade the non-default WAN would intermittently lose connectivity and show as 100% packet loss. The weird thing about this one it would only drop the non-default gateway. The default gateway was always up. So if I swapped the default, the packet loss would also follow the other non-default gateway. So I knew this wasn't a hardware problem, For the past 4 months I have been trying numerous troubleshooting steps including a complete reconfigure of my pfsense setup from scratch and nothing worked, at least not until I added 'supersede dhcp-server-identifier 255.255.255.255' under "Option Modifiers"
Thanks again, this saved my sanity. :)