Any advice on how to attain lateral stability and control? My aircraft has a rolling motion to the right despite being completely symmetrical. It's manageable until I hit around Mach 3.5, then the aircraft begins rolling out of control. It's not dangerous by itself, but an uncontrollable roll rate at Mach 4.25 and 21,000 meters is concerning. I also have a very slow turn rate from the rudder, with the aircraft occasionally stopping its yaw motion and flying straight despite full rudder application. The aircraft also has a minor roll motion towards the inside of my turns. When I stop making turns the aircraft yaws left and right several times like a pendulum and while the motion dissipates it continues for some time.