I got the same issue, turns out it’s a bug from ChaosVehicleMovementComponent:
/ChaosVehiclesPlugin/Source/ChaosVehicles/Private
/ChaosVehicleMovementComponent.cpp
(https://github.com/EpicGames/UnrealEngine/tree/128c1721ae7c6169f98a17ede9fe220f9ac279cb/Engine/Plugins/Experimental/ChaosVehiclesPlugin)
there is a problem in function ApplyThrustForces, at line 369, change
FVector ThrustForce = VehicleState.VehicleWorldTransform.TransformPosition(Thruster.GetThrustForce());
to
FVector ThrustForce = VehicleState.VehicleWorldTransform.TransformVectorNoScale(Thruster.GetThrustForce());
it will fix the problem.