Customer Account not available & Supplier Number invalid in SCFO Profit Center BU Relationships

We are configuring Supply Chain Financial Orchestration (SCFO) and facing an issue while setting up Manage Profit Center BU to Party Relationships.

We have already configured Customer and Supplier in:
Manage Intercompany Customer and Supplier Assignments

However, when we try to use the same in Profit Center BU setup:

• Customer Account Number is not appearing in the LOV
• Supplier Number throws error:
  “The value of the attribute SupplierIdentificationId isn't valid.”