Disclaimer: I am posting this on superuser since this is about configuring the minecraft server (or possibly the client or network), not an issue with the game. If this is the wrong place, please comment with the correct stackexchange-site and I will move the question there.
Now to the actual problem:
I have set up a raspberry pi 4 as a minecraft server (PaperMC running on Raspbian), which works surprisingly well, performance-wise.
If I connect to this server via one of its v4 adresses (cable or wifi), everything works perfectly.
If on the other hand I connect using one of its global v6 adresses (again, cable or wifi), the game only loads one or two chunks (if any at all) and then times out after a couple of seconds.
Obviously, this is an issue if I want to be able to just give someone the server's static IPv6 adress in order to not bother with dyndns or similar workarounds for running a server behind an IPv4 NAT.
I am ruling out an issue with the physical connection or with the routing since both the PC I am testing this with and the Pi are connected to the same switch, as is the wifi-AP the Pi is connected to.
They can connect to each other over IPv6 using other protocols . in fact, I copied the minecraft server to the Pi using scp to its v6 adress.
Neither my pc nor the Pi have shown any other signs of trouble with IPv6 connections.
Are there any configuration options either for minecraft (server or client) or the server's OS that I am missing?
