Bitrix. Why does the mail template of another site work or is it sent from another site?

Question

1C-Bitrix

The problem is that mail templates are configured in the web form and when submitting the form from the "s2" site, the form is sent as if it was sent from the "s4" site.

Having made a sql query: select * from b_event order by id desc
The table also contains the site id "s4"

The site was not made by me. I did not find anything in the php_interface folder in the init.php files and the function.php connected in it that could affect this.
When sending from other sites, everything is fine, the mail templates are identical. I tried to add text to the site template "s4" to distinguish it from "s2". The letter comes with this text. In addition, #SERVER_NAME# is also substituted from s4, although the data (shop addresses) comes correct from s2.
What could be the problem?