Want to see what folks are doing in this scenario.
Two Mikrotik Routers. Each has an ISP pulling in default routes via eBGP.
Are you doing a separate instance to establish iBGP? If so, are you doing "redistribute Other bGP" in the instance? Client to CLient reflection?
in the peer are you doing nexthop choice "force self, propagate, or leaving at default"?
Using route reflect in the peer?