Why the heading is false in my MX20 hott :
FC in 252° i read on the MX20 252°
FC in 253° I read on the MX20 0°
FC in 0° I read on the MX20 100° and so on.
Y tested firm 1.41 and 1.85 of the MX20 no change and too reflash RX Gr24 ver: 03A78.
AQ firm R445
What can i do ,

Thanks for help
