Why exhausted CPA is being referenced in Requisition

1. RSSP create requisition, source: CPA, input required information, leave agreement field blank.
2. Enable automatic sourcing contract purchase agreements is enabled at PROC BU options.
3. After PR is approved, PO is expected to be created automatically. However, looks like it is defaulting the old agreement for which amount is already exhausted and below error is displayed (as expected since limit is exhausted)
   Your order will cause the total amount released against agreement **** to exceed its amount limit.
4. Multiple eligible CPAs are available. System does not check for other best available CPA as per the below rules. Why it continue to refer old CPA. Please advise?