proton vpn seems not fully functional

RouterOS General
1

Hi, I am testing now with a (free)proton vpn account. When I use it as open vpn client on the kodi machine itself, it works fine.
Then I disabled openvpn and configured the ipsec on a routeros. The vpn comes up, in firefox on the kodi machine i see the public IP indeed changed to the VPN exit point.
The videostream however does not start. Any ideas what I missed ??

#  RouterOS 6.48
/ip ipsec mode-config add name=ProtonVPN responder=no src-address-list=via_proton_vpn
/ip ipsec policy group add name=ProtonVPN
/ip ipsec profile add dh-group=modp4096,modp2048,modp1024 enc-algorithm=aes-256,aes-128,3des hash-algorithm=sha256 name=ProtonVPN
/ip ipsec peer add address=nl-free-07.protonvpn.com exchange-mode=ike2 name=ProtonVPN profile=ProtonVPN
/ip ipsec proposal add auth-algorithms=sha256 enc-algorithms=aes-256-cbc name=ProtonVPN pfs-group=none
/ip firewall address-list add address=192.168.88.91 comment="kodi" list=via_proton_vpn
/ip ipsec identity add auth-method=eap certificate="" eap-methods=eap-mschapv2 generate-policy=port-strict mode-config=ProtonVPN password=<passwd> peer=ProtonVPN policy-template-group=ProtonVPN username=<user>
/ip ipsec policy add dst-address=0.0.0.0/0 group=ProtonVPN proposal=ProtonVPN src-address=0.0.0.0/0 template=yes
2

Try following this guide: http://forum.mikrotik.com/t/nordvpn-ipsec-ikev2-killswitch-for-ros6/144817/1

EDIT: You may need to reduce MSS size and exclude such traffic from fasttrack. Everything is mentioned in the above guide.

3

Thnx! Indeed I overlooked MSS
Added these two, now all goes as plenned

/ip firewall mangle add action=change-mss chain=forward new-mss=1200 passthrough=yes protocol=tcp src-address-list=via_proton_vpn tcp-flags=syn tcp-mss=!0-1360
/ip firewall mangle add action=change-mss chain=forward dst-address-list=via_proton_vpn new-mss=1200 passthrough=yes protocol=tcp tcp-flags=syn tcp-mss=!0-1360