Thank you for your post, I have done some remote checks and can see that you are currently in an area outage you that would be affecting this, the estimated fix date is 12th Feb the reference for this outage is F007268423. If after the outage you are still experiencing issues with your picture we can book an engineer to come and have a look.
It was improved on Tuesday but back to terrible today - the day given as the 'fix'.
It cannot be my equipment because it isn't affecting all the channels. There is clearly an issue - seemingly on a day to day basis - with the signal for this channel in particular. How can it be okay one day and rubbish the next?