Hi @steveren . This user got an AX10 working on HFC. With FTTP, you don't need to worry about setting VLAN ID. If it is old, it may need firmware update.
Do you have the FTTP box already installed? If it is installed inside the house, that's ok. If it is inside the garage, you should get a longer ethernet cable (Cat6) so the router can be placed inside the house.