Zabbix GUI: Cannot connect to MariaDB Database using .PEM certificates

[PKWillzinho]

Hi Guys,

I'm having trouble setting up a TLS connection from Zabbix Frontend to a MariaDB database using X509 certificates.
Here's the environment I set up:

MariaDB Database Config:
ssl_ca=/etc/mysql/certs/CA-CERT.pem
ssl_cert=/etc/mysql/certs/DB-CERT.pem
ssl_key=/etc/mysql/certs/DB-KEY.pem
require_secure_transport=ON
bind-address = 0.0.0.0
port=3306

MariaDB User Config:
CREATE USER "zabbix"@"%" IDENTIFIED BY "zabbix" REQUIRE X509;
GRANT ALL PRIVILEGES ON zabbix.* TO "zabbix"@"%";

Zabbix GUI Configuration File:
$DB['TYPE'] = 'MYSQL';
$DB['SERVER'] = '172.16.20.131';
$DB['PORT'] = '3306';
$DB['DATABASE'] = 'zabbix';
$DB['USER'] = 'zabbix';
$DB['PASSWORD'] = 'zabbix';
// Schema name. Used for PostgreSQL.
$DB['SCHEMA'] = '';
// Used for TLS connection.
$DB['ENCRYPTION'] = true;
$DB['KEY_FILE'] = '/etc/zabbix/certs/ZBX-KEY.pem';
$DB['CERT_FILE'] = '/etc/zabbix/certs/ZBX-CERT.pem';
$DB['CA_FILE'] = '/etc/zabbix/certs/CA-CERT.pem';
$DB['VERIFY_HOST'] = false;
$DB['CIPHER_LIST'] = '';

Zabbix Server Config:
DBTLSConnect=required
DBTLSCAFile=/etc/zabbix/certs/CA-CERT.pem
DBTLSCertFile=/etc/zabbix/certs/ZBX-CERT.pem
DBTLSKeyFile=/etc/zabbix/certs/ZBX-KEY.pem
DBHost=172.16.20.131
DBName=zabbix
DBUser=zabbix
DBPassword=zabbix
DBPort=3306

When trying to access Zabbix Frontend I get an error:
Database error
Database error code 2002

¹ Zabbix Server can connect to MariaDB normally.
² If I use the following command line from Zabbix Server I can also connect normally:
mysql --user=zabbix -p --host=172.16.20.131 --port=3306 --ssl-cert=ZBX-CERT.pem --ssl-key=ZBX-KEY.pem --ssl-ca=CA-CERT.pem

All certificates were generated and tested with OpenSSL 1.1 and Apache2 is our Web Server.
I need to implement this layer of security with certificates in our Zabbix environment, but this issue is holding me back... Could someone help me with this?
Thanks...