I've got 2 edge routers, each with a fiber connection to my ISP (2 separate circuits, same ISP). I've got my public ASN, and BGP is working properly with my ISP on each of these routers. What I need to set up is failover...so if one router's neighbor fails than my outbound internet traffic automatically fails over to the other. I assume I need to set up iBGP peer group for these 2 routers?
Based on what you have described here it is possible that there is some problem with how you advertise your networks to the ISP from the second router or there could be a problem on the ISP side about receiving those routes. I would suggest that we start by looking at how you advertise your networks to the ISP from the second router. Can you post the config (at least the BGP parts) for the second router?