When I wrote http://forum.mikrotik.com/t/mikrotik-behind-nat-to-mikrotik-ipsec-ike2-with-certs-tunnel-eoip/144952/1 I was using ROS7 as a VPN client to ROS6 VPN server. EoIP did work, but was silently flapping leading to random disconnects from online multiplayer games. Disabling keepalive in both sides fixed the issue.
Can this be related?