I have purchased a new DSE 7500 Freeview receiver and a dish with a Sharp KU-LNBF LNB

I have set these up and the box is tuning to Optus D1 , Carrier 2, on 12456 MZ , but the best signal I can get is a Polarisation of 81% Vertical and 63% Horizontal

This gives me a clear picture for all Freeview channels apart from TV1 , TV2 , TV6 , and TV7

Any clues on why these 4 channels are missing ?

MANY THANKS