Can we correct a terminated assignment record?

Summary:

We are trying to correct the People Group of 800+ employees' inactive terminated records. We are correcting the latest action record which is the Termination action.

However, we are getting an error "Error: The message is : An error occurred. Contact your help desk."

Same are happening in Classic UI (Person Mgt), Loading HDL, and Responsive UI (Employment Info). Please see attached files for the error and for sample HDL file.

Content (required):

Note: This error is only happening on the latest Termination action record (e.g Voluntary Termination). When we try to correct the Hire action record as below, we are able to correct it.