Jagging behavior in hinge moment-rotation curve

[Allaaldeen]

Hi all
in dynamic analysis, I am getting Jagging behavior in hinge moment-rotation curve when the stiffness changes to negative as shown in the pic in the link below
I am using ModIMKPeakOriented material for the plastic hinges. I got the same jagging using the Hestritic material.
under cyclic static loading, the moment-rotation curve was smooth.
Can you please give a reason for this jagging?
https://ibb.co/qp4VkWB