The Kunos solid rear axle implementation is proving to be real enigma.
If I'm not careful I get infinite roll stiffness or even infinite bounce/jounce stiffness. (or somewhere inbetween)
The earlier versions suffered as a loss of lateral traction seemed to hang around for much longer than it should have.
Perhaps the rear geometry was pushing itself into a position where it ran out of compliance.
The rear end now has only one pivot, as it is real life, and is only located laterally by the leaf springs.
I ran into infinite roll stiffness with my oval cars, but was surprised when I created an arrangement that gave full roll compliance but infinite bounce/jounce stiffness.
Had to revisit more than one of my cars to repair this.