I have a Vigour 2860 with ethernet cable connected to my Dreambox DM800se satellite TV receiver which also runs my IPTV.

It's run perfectly for about 3 years like this but now seems to stop the internet even if it's not streaming any TV. As soon as I unplug the ethernet cable to the Dreambox the internet is back.

I have a fast fibre optic connection at about 50 mb/s which is very reliable so it's not a band width issue when streaming.

What could be causing this?