Pixelation - is this due to the Solos tuners?

I have a VU Solo SE v2 running cable and 2 tuners from 1 physical connection

I am getting pixelation on some HD channels but not all.
SD channels are fine.

I am running the latest Vix image and also recently flashed the box.

My power levels coming in are 7.9 max and this is split to BB router and Solo box.

Any suggestions on what to do here as Im a bit lost now.
Could this be a VU not able to handle twin tuning internally?

Cheers Bart