Cannot connect to Home Assistant using ddns IPv6

Hello,

I have had a Vodafone DSL connection with DS-Lite since this week. I am now trying to access my Home Assistant from outside. It is an HA OS on my Proxmox.
I have a Fritzbox 7590AX and the custom componentr duckdns_ipv4_ipv6 configured.
I have enabled ports 443 and 8123 in the Fritzbox.
In DuckDNS I see the correct IPv6 address of my VM and only the IPv6 address. And when I open this IP from outside in the browser [xxx:xxx:xxx:xxx:xxx:xx:xxx:xx]:8123 I get to my server. But not with mmydomian.duckdns.org:8123.

I hope someone can help me.

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I have exactly the same problem.
Does anyone have a solution?

The problem seems to be that port forwarding is not working for the domain because of DS-Lite. Because IPv4 is used.