My Vehicle ends up toppled to one side, with the right wheels embedded into the ground.
The imported mesh and bones for the wheel axis look all aligned and OK in Blueprints and Physics constraints views. I adjust Both the front and rear Wheel BPs Wheel Radius, to reduce depth into Ground. The Two front are same size, but different to the two larger drive rear wheels. But left to right the sizes are the same on the axis. But with larger wheels at the rear, the axis (bones) are higher.
But that would not explain why vehicle sags at an angle to the left. The front wheels in game play are no longer aligned on the axis, despite looking OK in the Skeleton Mesh, Physics and Blueprints views.