Bcc of order sent to wrong email address

Hi there!

I’m using Mageplaza SMTP modul for mail handling. All the SMTP settings are OK, test email is sent to the correct email address. I’ve set up the Bcc email for order, invoice and shipping emails. But it is not sent there. We found out in server logs that it is sent to another email, that is no longer in use (we used it just for testing). These settings are in Stores > Settings, Configuration -> Sales > Sales Emails. Whatever I change there it does not work – the carbon copy always gets sent to the wrong email.
(this thing works on our other M2 webshops)

Are there any other settings for emails in M2 dashboard? Is there maybe a setting directly in the database?

The Magento version is 2.4.2-p1

Any help will be much appreciated!