Hi Smevster
Sorry to see you are having pixelation issues on SKY Sports UHD channels.
You've probably already done this, but make sure all your cabling is tight and free from any kinks, staples etc, especially the white coaxial cable as that can cause pixelation problems. Also check your HDMI cable is properly seated, and if po9ssible try another HDMI cable and/or socket.
Also have you used the /check-services/ function? You can also a run a test on your equipment from there. If nothing is showing you could also try the automated Service Status number 0800 561 0061. This often gives details of more local issues down to postcode level.
The only two full time Sky Sports UHD channels are Sky Sports Main Event UHD and Sky Sports F1 UHD.
The other two Sky Sports UHD channels are part time and thus named Sky Sports UHD 1 and Sky Sports UHD 2 and when they are on they will broadcast a UHD version of any of the normal Sky Sports channels. It looks like the Sky Sports UHD 2 channel has been broadcasting a simulcast of the Sky Sports Cricket channel (504) in UHD
The channels are broadcast in muxes, rather like the way Freeview channels are set up, and so the Sky Sports UHD channels aren't all grouped together.
Sky Sports UHD 2 (the one the Cricket UHD is currently on) is in the same mux as all of the FAST channels (no other normal broadcast channels are on this mux) but I would expect all of those FAST channels to be affected too if it's a signal issue.
Sky Sports Main Event UHD is on the same mux as Blaze, Comedy Central Extra, That's Memories, Nick Spongebob, Nick+1, and Nick Jr PAW Patrol. Again if it was a signal issue I would expect those other channels on that mux to be affected.
The EFL Football in UHD was broadcast on Sky Sports UHD 1. That channel is on the same mux as Movies 24, Movies 24+, Quest Red, Food Network, SONY MAX2, QVC Extra and QVC Beauty. Again if it was a signal issue I would expect those other channels on that mux to be affected.