Yeah, it’s just that nasty “rigid body + Nlgeom + shells = non-convergence” limitation of CalculiX. It’s explained by the CalculiX dev here: Rigid-body constraint convergance problems - #25 by dhondt - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).
Here you can find a list of various CalculiX limitations with workarounds: Known CalculiX limitations