Stream from outside the network breaks off - Issue solved?

[Burkhazad]

Check if your local and public ip changed.

Check if domain is not blocked.

Speedport is set to DHCP for the entire network, but to a fixed IP directly for the server (directly in the router settings).
I have also set up port forwarding to TCP80/TCP443 and UDP80/UDP443, which points directly to the server from the router.

DynDNS service is NoIP and "DUC" is also running automatically on my normal computer, which performs a synchronization.

Domain is not blocked (I think, how does this manifest itself?) I can access my domain from all devices, whether from inside or outside.

Movies also start to play, for 10-20-30-40 minutes and then it breaks off or simply stops.