WireGuard as a "client" work with IPv4 not IPv6

[learningalways]

Hello,

I have followed the instructions on this link to configure WireGuard as a “client” of a remote VPN through which I would like traffic to the internet to be routed.

So I configured the tunnel and its peer:
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Then the interface :
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I haven't created a gateway group because I want the connection to break if there's no VPN.

The outbound NAT rule created itself for IPv4 and I added this one for IPv6:
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Then I modified the default gateways:
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Under these conditions, IPv4 works and is routed through the tunnel. However, it's as if the IPv6 doesn't want to pass through the VPN. (here's an example, trying a simple ping)
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If I reset the IPv6 default gateway on my WAN, the connection is working :
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I've tried several things, but without success... Would you have an idea please?

My verison of pfSense is 24.11.

Thanks in advance for your help.