Lightbox: Thanks.
I am not intimately familiar with Fritz Box, but is there some sort of built in firewall etc. that might be blocking some traffic? If so, maybe you could try turning it off to see if that's what's causing the issue.
I don't think there is a firewall blocking anything, I have UPNP enabled so that the PS4 can open the required ports automatically. I have contacted Sony but I wont get a reply for a few days, they probably wont be much help.
I'm going out now but when I get home I will try download quickflix and see if I'm blocked on that.