Since you are trying to advertise the routes which were learned from an eBGP peer to your iBGP peer, the next hop is still pointing the soure IP of eBGP Peer.
Branch router sees the Lo0 route coming from 10.0.0.2 which it does not have the reachability to.
To resolve the problem, ISP1 sets a "next-hop-self" toward Branch router so that it know where to go.
http://www.getnetworking.net/bgp/bgp-next-hop-self
I'm not sure if Meraki tech can do that for you...They could help another user to set the "multi-hop"option which is not available to us.