Redwood Requisition: User unable to update Requisition Preference

When user logs in into RSSP page, she is getting a pop-up to update Requisition Preferences.

When the tries to do the same, she is unable to update BU in Requisition Preference. with below error, screenshot attached.

The value provided for the requisitioning BU isn't valid. (POR-2011158) Details: Either the business unit doesn't have an active requisitioning business function, or the logged-in user doesn't have access to the BU.

Note: This issue is only specific to 1 user as of now.

Kindly Advise