The Suggested Buyer visible/editable via VBS on Edit Requisition Header but need to enter it twice

Summary:

I have made the Suggested Buyer field on the Edit Requisition header visible and editable via VBS. But when editing the RQ header the suggested buyer needs to be entered twice. I can select a buyer in the field, but when clicking OK the buyer field returns empty. I need to perform the action twice.

Content (please ensure you mask any confidential information):

Edit Requisition Header:

Buyer can be selected, when clicking on the name the field becomes empty.

And I need to select the Buyer once again.

Selecting the buyer for the second time, keeps the buyer on the screen.