IPTV freezes after 10 seconds. Multicast Storm?

So I wanted to get IPTV running, but I keep getting freezes at around 10 seconds of streaming. I don't know if my configs are wrong or if something else is blocking things, but I really need help. I'm using a FB4040 and a Cisco layer 3 switch between my IPTV and my router. In front of the router, there is a vigor167.

If someone could let me know how I can upload my config files, that would be great.

Best
Kilian