Minecraft Server - Port Forwarding with Unitymedia Router is not working, any ideas?

I built a server from remaining PC parts today.

Immediately I thought about creating a Minecraft server that should be reachable outside of my home network. I have already created the files for the server, Vanilla 1.14.4 - he runs and you can easily access the local network, as it should be, I have identified DHCP, otherwise the IP changes at each reboot and a static IP configured,

Now I have in my Unitymedia router TC7200 (Yes, a bad model for some), the ports 25565 for UDP & TCP enabled, but it is there IPv6 Forwarding, the question is whether that matters and it is not possible. Afterwards I put together the public IPv4 address with the haven, however the server is not attainable according to my colleague.

Then I tried the server itself to release the ports in the firewall, ie UDP & TCP with each incoming and outgoing rules. Still does not work after that. The same thing on my PC, just had no colleague to test, so I could not quite try it.

But I should still come with the public on the server?

I hope you can help me, it has always been a huge dream to host a server at home where friends can play and you can always make changes without being limited.

So first, you have to disconnect your PC from the cables. Lift it up, go to the window (open the window in advance) and throw it out of the window with a little swing.

I hope your question has been answered (͡ ° ͜ʖ ͡ °)