Unable to remove the Create Bank Account at Supplier Site level

Summary:

ERP 26C

We have AP users that should be able to create supplier but NOT supplier bank accounts. We created custom roles of Accounts Payable Manager, Employee, Supplier Manager etc and removed the privilege Manage Third Party Bank Account. This works fine and supplier accounts cannot be created.

We now need a sysadmin user that can do almost all ERP related setups EXCEPT create supplier bank accounts. So we created a custom role of Financial Application Administrator and ensured it does not have Manage Third Party Bank Account privilege (Created inherited custom roles etc).

We find that the Supplier Bank account cannot be created at Profile and Address Level (Can be viewed only which OK) but at Supplier Site level the Creation Icon is still there and I can't see why. It seems that another privilege is controlling this at site level. What is it?