I had to set the ethertype on the new WAN bridge to 0x9100 in order ... Most of the time they were wanting to put the fiber directly to the router instead of using Ethernet to the ONT.

a Fiber-optic ONT, a gateway, or another router — via its WAN port. After that, the rest of the broadcasters work as ...

You get a 10GbE SFP+ uplink port for long-distance connections over fiber, and a neat touch ... configuration for the WAN ports is simplified by the router’s Smart Queue Management (SQM) feature.