Hello,
I think that the problem is that after primary link comes up again , BGP routes are not valid for same reason and are not installed in routing table.
Could you send us the out of the following commands:
1- Normal state (primary link up)
show ip route
show bgp ipv4 unicast summary
show bgp ipv4 unicast
2- Primary link down
show ip route
show bgp ipv4 unicast summary
show bgp
3- Primary link comes up again
show ip route
show bgp ipv4 unicast summary
show bgp ipv4 unicast
Regards.