Pixelation when watching BBC.

[T60Ken]

When I watch BBC 0ne or two and sometimes ITV my screen constantly pixelates. This was very noticeable during Wimbledon and the Euros. Even when I used the BBC iPlayer app through sky Q it would still happen, however if I switched sky Q off and used the BBC iPlayer directly through my sky broadband there was no issue and I could often get an HDR picture. Why is this the case? It is very annoying having to come out and log in etc., when I am paying for a service through sky Q that should work.