OTL: Unable to select PO in time card for contingent worker

Hello Experts

I am in the process of submitting a time card for a contingent worker, i am unable to select a PO from the list of values
Steps to reprodue the issue

1. create a requisition for a contingent worker
2. Convert to a PO and approve the PO
3. Create a contractor assignment
4. Step 3 should create a record in HRMS
5. Create a user login for contignent worker and assign OTL access
6. Contingent worker logs in and when he clicks on PO to select value, user is getting an error as attached

Thanks

Dilip