JointSpringForceField scene not working

[hugtalbot]

This scene appears not be working. It is possibly linked to #2777 and #3967 but I do not see why
This might be a known case for interaction FF @alxbilger but I do not recall why or the change to apply

Until v23.06 :

JointSpringForceField__r60_0001.mp4

Since v23.12 and now:

sofa_video_r60_0001.mp4

[alxbilger]

I would be surprised as the component did not implement addKToMatrix...

[hugtalbot]

I understand that the scene should not work with implicit schemes + direct solvers but here it's a CG
addDForce should it then

[alxbilger]

I suspect the RigidMapping. There are forces in the mapped DoFs, but I see only gravity force in the main DoFs.

[hugtalbot]

Then a real bug, I will try to find some time to investigate