Hi Cast287,
A warm welcome to our community 
I'm sorry to hear that you're experiencing picture disruption when watching Coronation Street. I'll be happy to help check this out for you.
I have taken a look at your boxes and all looks great signal wise right now. If you're still experiencing an issue with the picture, please get back to me with the following information:
* Does this affect all boxes in the home?
* Are other channels affected?
* Are the box/es overheating or are they well ventilated?
* Does this happen all the time or at various times of the day?
If you can let me know I can help further.
Collette