This is a peer support group. You should contact customer support.
That being said I don't believe you need to have the ont provisioning changed as with your router's coax port connected to the house internal coax wiring and the ethernat wan port connected to the ont traffic should be bridged between the ethernet and coax sides. I've never done it but it obviously works for the 100 Mbit plus tiers as they are always ethernet connected to the ont and the STBs are connected to the router via coax.