I've mount a Norsat + CR229 flange. feedhorn
I've try a test with dielectric plate on Astra 5E with a Triax 120cm and the LBN works fine.
Later i've mount the same LNB on my Gibertini 150 (with the same dielectric plate) i've try the same scan on the same satellite.
In this case i've a list of duplicate TP in H and V.
Do you have a better idea now ?