Have issues setting up IPv6 VPN in OPNsense

[twistabled4alt 0]

Hello,
I have set up AirVPN following this guide : https://airvpn.org/forums/topic/67976-howto-opnsense-using-wireguard-with-ipv6-support/ , it worked pretty nice for ipv4, but I got problems with ipv6.

I don't really have the same setup as in the tutorial as to make the IPv6 works I had to setup the LAN interface IPv6 to follow the IP of WAN, which in this case return the correct IP.

 

But there is a problem, I've setup NAT (I know it shouldn't really be done this way...) for IPv6 but the translation is not really working and ipv6-icmp requests doesn't work.
If someone here could be helpful, I would greatly appreciate it!
Have a good day.