Hi @gbansal
Sorry to see you are having problems with pixelated channels on both boxes. You've done the correct thing by checking cables are snug and tight. I would also suggest checking externally where the cable comes into the house and also ensure the white coaxial isn't twisted or loose.
Are you in Scotland by any chance?
Channels are grouped together in muxes, rather like they are on Freeview, which doesn't correspond with their EPG placing.
On a 360 BBC One Scotland HD and E4 HD (channels 101 and 106) are grouped in the same mux as the channels shown in the screenshot below. If you are having issues on those channels as well then that would seem to indicate a signal fault, and would require an engineer visit since you are having the same issue on both boxes.
Have a look at the online Check Service Status at the top of the page to see if anything is showing there. If nothing there then also try the automated Service Status number 0800 561 0061. This often gives details of more local issues down to postcode level. If nothing is showing on there either then call in and report the fault, or wait a few days for a member of the Forum Team to pick this up..

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