So basically you built ROS-based IPSEC/IKE2 VPN server like this:
- http://forum.mikrotik.com/t/ipsec-ike2-with-certificates-vpn-server-guide-for-remote-access/149434/1 ← proper implementation of Mikrotik IPSEC/IKE2 (certs-based) VPN server
- http://forum.mikrotik.com/t/mikrotik-behind-nat-to-mikrotik-ipsec-ike2-with-certs-tunnel-eoip/144952/1 ← Mikrotik to Mikrotik connection, in this case use this guide only for additional guidance and nothing else
Then I believe you should be following this guide for connecting to VPN server from Mikrotik: http://forum.mikrotik.com/t/nordvpn-ipsec-ikev2-killswitch-for-ros6/144817/1
Anyway, I do have a feeling that it has something to do with NAT:
The connection is established and transmits data without any receive.
Otherwise, I am not sure where is the problem.
EDIT: Try to reduce MTU/MSS size in both client and server configs for VPN traffic. It might be related. More info here.