Is it possible to Add Line/Matrix manager to an inactive assignment

Summary:

We have successfully enabled the creation of performance documents for employees with inactive assignments. However, we are facing challenges with the approval workflow routing.

Issue Description:
The approval workflow is currently picking the assignment manager instead of the manager defined in the performance document.
To address this, we introduced the Matrix Manager concept so that the workflow can route approvals based on the performance document hierarchy.
Challenge:
The employee’s assignment is already inactive, and the temporary assignment (which had manager details) is end-dated.
As a result, there is no active manager information available in the system.
When attempting to update or add a Matrix Manager, the system does not allow saving changes due to the inactive status of the assignment.