Zabbix server has DBTLSConnect parameter which controls enable TLS or not and, additionally, level of SSL verification. It supports three values: required, verify_ca, verify_full.

Zabbix web-interface has two checkboxes "TLS encryption" and "With host verification".
The behaviour of these two options are not clear in comparison with Zabbix server configuration.

Although "With host verification" does not make sense for MySQL database at all. It is not used in MySQL connection configuration. It is available only for PostgreSQL:

include/classes/db/PostgresqlDbBackend.php:				'sslmode' => $this->tls_verify_host ? 'verify-full' : 'verify-ca',

Anyway, PHP module for MySQL (mysqli) has two options:
MYSQLI_CLIENT_SSL - Use SSL (encryption)
MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT - Like MYSQLI_CLIENT_SSL, but disables validation of the provided SSL certificate. This is only for installations using MySQL Native Driver and MySQL 5.6 or later.

So it is expected to have the same configuration view / options for server / proxy and web-interface + similar behaviour.