I am using my own-written UMAT subroutine in a contact problem in ABAQUS. It works well in modelling uniaxial and biaxial stretch forming of a  plate. -Meaning my UMat subroutine is OK ! -

But when I use it in simulation of a stamp forming press  , it doesn't work!

However my stamp forming simulation works also well when using deformable-plastic material instead of my UMAT subroutine. - so it seems my contact simulation is OK too -

I tried to apply some of the mostly recommended suggestions in different forums like: only using 1 Cpu but it doesn't work for me!

So I am really stucked !

I appreciate any recommendation and suggestion