Romfarer

IDK why propagateControlUpdate should be failing, since a ship being in orbit or in an atmosphere should have no bearing on whether you're able to control it or not.

The fact that you can control the vessel's throttle indicates that the input sending is working properly, but I'm afraid I can't be much more help in finding out where exactly the problem is... not without seeing all of the code involved. I can only advise you to double-check you're propagating the input state on the vessel's root part, and that the vessel is unpacked and able to be controlled.

Cheers