DKIM signature and OpenSSL 3.0.7

[TheHolbi]

I have just migrated a CWP installation from Centos 7 to AlmaLinux 9.4 by migrating the /home directory, the /var/vmail directory, and the databases.
All the features have been configured, but I have two problems that I have not yet managed to solve.
AlmaLinux 9.4 was installed with OpenSSL 3.0.7   1 Nov 2022 by CWP, and none of the programs, even a Laravel 11.x app under PHP 8.3.12, can send mail over port 465.  
Error message:

Connection could not be established with host "ssl://mail.example.com:465": stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:
error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed {"exception":"[object] (Symfony\\Component\\Mailer\\Exception\\TransportException(code: 0): Connection could not be established with host \"ssl://mail.example.com:465\": stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:
error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed at /home/user/laravel/vendor/symfony/mailer/Transport/Smtp/Stream/SocketStream.php:154)

I had to temporarily switch to using port 25 in the SMTP service.

The other problem is that postfix does not put DKIM signatures on the mails, even though all elements of the system, OpenDKIM, etc. are installed and running.
What should the config file of postfix and opendkim look like in CWP to get this service working properly?