Customer bank account available in Supplier invoice payments

Dear community,

We have a supplier that is also set up as a customer (same party_id).

The supplier has a bank account named number LV61HABAXXXXXXXXXX669 with EUR currency. The customer has a bank account with the same number LV61HABAXXXXXXXXXX669 but with different name and unspecified (null) currency.

The "Search Supplier Bank Account Assignment" form shows only the supplier bank account as expected:

The problem is than when creating payments for the supplier's invoices the user is able to select both the supplier and the customer bank account in the Remit-To Account LOV. Why is the customer bank account which is not assigned to the selected supplier site visible in AP payments and how to prevent that?