The problem is solely in the LJ35. I have the free PMS GTN750, and I had a pre loaded valid flight plan. I followed exactly your described steps, with the difference being that with the GNS530 LNAV will arm, but with the GTN750 it won't.
Hello there,
with the PMS GTN750 variant, I am unable to arm the lateral NAV mode. I have a valid flight plan, but the mode will not arm. With the GNS530 this works just fine. Version is 1.3.0. Any help for that?
best regards