OpenVPN and IPv6 not working at Vultr

[tuxboy]

Hi Everyone,

I am trying to setup a VPN gateway at Vultr with the Opnsense and OpenVPN.

It runs on TCP on IPv6 and IPv4.
Connecting by either IPv4 or IPv6 is not a big deal.
IPv4 Connections to the internet work fine.
IPv6 is not working.
I talked with the Vultr network team they say it is a Problem with the VPN clients IPv6s not answering to NDP.

Does someone know about the Problem?
I searched in the forum but the Search listed every singel entry with OpenVPN and IPv6 not sorted after threads and i could not find my Problem.
The main IPv6 is answering just fine with all tests.
I can Ping Google and everything.
Could someone pleas assist in getting the Public IPv6 connection to run?

regards
Tuxboy