VPN IPsec - no traffic when FEC enabled on both sides

Hi everyone,

I have an issue I can't understand. Explanation :  I have a dialup tunnel ipsec vpn between two fortigates (one with fortios and one with forti100( dialup client) ). Everything is fine. I have activated FEC  on the fortios side, everything is fine.

My issue is when i activate FEC (egress and ingress) on the forti100 side, the tunnel is up but no traffic passes. Question : is activating FEC (forward correction error) on both sides a good idea ?

Thank you !

Best regards

Vincent