I have just installed Flightgear for the first time. Everything seems to work like it is supposed to, except that the control surfaces, ailerons, elevator, and rudder, move erratically. At first I thought it might be a joystick problem, but it does it even with keyboard controls, even without the joystick plugged in. It is virtually impossible to fly the aircraft, because the control surfaces jump around and center uncontrollably when trying to do any kind of action with the yoke. When the view is from behind the plane, you can see the elevator, rudder, and ailerons jumping around and resetting to neutral rather than smooth control.
I hope there is something I can do to make it work, because I know I will love the program if this issue is resolved.
My computer is an HP Presario, 16gb memory, 8 core processor, operating system is Ubuntu 20.04..2 LTS, Flightgear version 2020.3.1, the graphis card is Nvidia GEforceMX150pci.
The problem seems to happen on all aircraft at any airport.
The scenery is the standard scenery from the system.
I also tried it on an older computer with a PureOS operating system (Linux) and it had the same problem.