VPN IPsec - no traffic when FEC enabled on both sides
I have an issue I can't understand.
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 !