Hi, Juan, Calc_em
Thanks for looking at this. The problem has been puzzling me for some days.
I think Nonlinear analysis has some deeper issue with offset shells. I will pay attention if I find some other examples.
Just in case someone else finds some issues converging offset shells I have been able to solve it just creating three parts and connecting them with tie contact.
Problems suddenly disappear , convergence is then sweet again.
Thanks again for your help and merry Christmas everyone.
