Object Creation - Assignments

Hi all,

On the "Contract's" metadata card, I have two properties ("Budget Owner" and "Business Owner") where I define the persons who will receive assignments. I want to ensure that if the same person is assigned to both properties, only one assignment is created, not two.

Since my assignments are created using the Property Calculator - Object Creator, I tried setting an Advanced Condition that Budget Owner != Business Owner, but it didn't work. I also tried using the Create Only If Not Exist option with conditions to ensure the "Assigned to" property is not the same, but that didn't work either.

How can I achieve this?
Thank you!