Hi @minch as an update for the thread, the problem seems to have been caused by the powerline adapters, you connected up a second set you had, and the issue stopped.
Thanks for confirming that, please post back if you need help with anything else 🙂
Was this ever sorted. I’ve been having this issue for a week. I rang Bt but they have no idea, asked me to reset the box, obviously I’d reset first before calling up.
its infuriating what’s the point having channels if you can’t watch them. All other channels are ok but all BT sport channels comes up with a black screen
Sorry for delay in replying, have been away without internet access (was fab!).
Anyway the forum tech was amazing in sorting my problem - basically the Youview box won't work with in built ethernet if your network involves a network switch before the router (this was my deafult set up) - even if streaming sites work, the multicast BT sport will not - it gets some signal which is why the screen goes black, enough to stop a no connection error but not enough to show anything - hence the black screen. I had tried 1 set of powerline adaptors, but these were faulty, a second set and it all worked and has since! So I've just left the yu view box connected via powerlinb adaptors directly to a LAN port on the router (for me this is a TP-Link router), but should work the same with the HH.
Hope this is not too late to help, thanks to the Forum again!
Glad it's all sorted for you but for information in general there's no issue with network switches as you have been told. I've used that set up for many years without issue with multicast transmissions.
It is important that any switch supports IGMP Snooping otherwise the whole network can get flooded with the multicast data and see all sorts of problems. For those with Sky Q Mini boxes it can be fatal.
Mine are just v boring TP Link 5 port switches (TL-SG105) which do support IGMP snooping, with each connected directly to 1 LAN port on the TP-Link router, so no idea why my set up didn't work (tried differents cables etc), but it does now via the Powerline adaptors so all happy!