The issue is dynamic dhcp routes have no option to ping the gateway, so if the physical connection remains intact, but the internet feed goes down, the router thinks the wan is still up and does not switch to the backup #2.
I found on the forums this command that allows a dynamic dhcp route to ping the gateway:
/routing filter add action=passthrough chain=dynamic-in disabled=no set-check-gateway=ping
This seems very simple and fool proof. Are there any drawbacks to using this method?