Hi,
Check all payment method in other bank journal.
Remove wrong provider link to bank journal (you may hace to switch to "manual" to be able to remove it).

You should be able to create new journal after.

Issue may come when you duplicate the provider and the first available bank journal available ( select by Odoo)  was multicompany or link to the company that already had a bank journal for your payment method.

Regards

Reasons:
1. Unique Payment Methods: Certain payment methods, especially those involving external integrations like MyFatoorah, need unique configurations to avoid clashes in API keys, credentials, or callback URLs.

2. Company-specific Configuration: Odoo enforces this to ensure that each company's payment method configuration does not interfere with another. This is particularly important in multi-company setups where separate financial operations are crucial.

Solutions:
1. Go to Accounting and select Configuration > Payment Acquirers.
2. Create new Payment Acquirer and fill the necessary details and configure the MyFatoorah payment method specifically for 2nd company.
3. Then back to accounting module, under the configuration > journals, create new journal for the 2nd company and link the created payment acquirer for Myfatoorah to 2nd company.

Hey!

I have the same mistake. Did you manage to figure out what is wrong?