Rings on TV screen like ripples on a pond

[TVrings]

I have a QE55S95BA TV. On some programmes there are circles that appear on the screen. Its not all the time. I receive TV signal via a cable system. I am unsure if it is a setting on the TV but I have tried everything. As it is not all the time its tricky to work out how to change it. 

[Gurky]

Usally thats down to the content being very low bitrate

[JAMES4578]

It could be  content not being upscaled particularly well, have you taken a picture Test to see if anytrhing is flagged  up just in case.  Go to Support-Device Care-Self Diagnosis-Picture Test.

[TVrings]

Thanks but I had already done this and the picture was fine.