IPsec and Webssl FortiGate behind FortiExtender

Hello,

First thank for your help.

For information i have create a case with the support to solv this problem. I will update this topic if i have news.

So i have 2 site :
-X: have a FortiExtender 4G LTE connection, FortiGate -> LAN
-Y: have Router ISP fiber, FortiGate -> LAN

Firstly at "X" i want to configure SSLVPN Webmode to manage FortiGate from Internet. So i configure FortiDDNS because i haven't fixed IP with 4G LTE connection.
Generally for example with a profesionnal router ISP you can simply access to "https://XXX.fortiddns.com:443" but you can't with standard public router. You have to configure Bridge, DMZ or do an ACL to allow all the traffic to the FortiGate. So maybe i have to configure the same thing on the FortiExtender ? I really don't know because "X" LAN can access to the webpage interface but we can't from Internet.

Secondly i want to configure an IPsec VPN between "X" and "Y". Here i configure the tunnel with "Dynamic DNS" on "Y" to communicate with "X".
But the tunnel don't work and i don't understand why but i think my 2 problems have one thing in common.

Regards,
hixeN