AR Impact on updating the account owner for a customer and Suplier

User is trying to remove the NOK currency restriction from supplier "A"(earlier named as "B") AS however I am getting an error that says this bank account already exists. Oracle engineer said this issue Occurred because of same combination (bank, account name, bank account, branch and null for currency) is already added on the customer GroupM Norway AS. Oracle engineer concluded his finding by stating that
The IBY validation is built within the application code and cannot be overridden:
All the external bank accounts are stored in the IBY_EXT_BANK_ACCOUNTS table, and each record should be a unique combination of the below: