Is it a static IP or DHCP from the ONT? - The Zyxel was configured to static IP, the Edgerouter to Dynamic - I will try configure the Edgerouter to static as well.
Does it need authentication for PPPoE - I dont know how to check this.
How have you set up eth0? - I used the wizard option for wan + 2lan2 so basically eth0 for Internet and all other ports bridged to the same lan.