Person Number field returns invalid value error

Summary:

While trying to assign a person as local/alternate manager using the Change Local/alternate manager widget, upon entering the person number, the search value returns Error : Invalid Value (assignment ID) .

Content (please ensure you mask any confidential information):

The search results two values one pertaining to EMP and other to PWK, but upon selecting either one of them, the above mentioned error is returned.

I have run the required diagnostic tests to validate if there is any data corruption, but no data corruption was reported.

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