Unicenta POS can't connect to mysql 5.7 on Debian 11

Question

Basically I can't get Unicenta opos to connect to a fresh install of mysql server on Debian 11. I have set up a user and granted privileges in mysql, created a new database named MAINDB and for some reason Unicenta won't make it connect....

a bit more info :

    mysql> status
--------------
mysql  Ver 14.14 Distrib 5.7.36, for Linux (x86_64) using  EditLine wrapper

Connection id:          7
Current database:       MAINDB
Current user:           root@localhost
SSL:                    Cipher in use is ECDHE-RSA-AES128-GCM-SHA256
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         5.7.36 MySQL Community Server (GPL)
Protocol version:       10
Connection:             127.0.0.1 via TCP/IP
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    utf8
Conn.  characterset:    utf8
TCP port:               3306
Uptime:                 10 min 16 sec

Threads: 1  Questions: 19  Slow queries: 0  Opens: 106  Flush tables: 1  Open tables: 99  Queries per second avg: 0.030
--------------

unicenta config screen

unicenta error

Any ideas?

OS info (hostnamectl): Operating System: Debian GNU/Linux 11 (bullseye) Kernel: Linux 5.10.0-8-amd64 Architecture: x86-64

mysql> SHOW GRANTS FOR unipos;
ERROR 1141 (42000): There is no such grant defined for user 'unipos' on host '%'
mysql> select host from mysql.user
    -> ;
+-----------+
| host      |
+-----------+
| localhost |
| localhost |
| localhost |
| localhost |
+-----------+
4 rows in set (0.00 sec)

I also had run the

GRANT ALL PRIVILEGES * . * ON 'unipos'@'localhost';

and

FLUSH PRIVILEGES;

after creating the unipos user.

This is the error message returned by Unicenta :

com.openbravo.basic.BasicException: Unable to connect to your Database Server!
Please check User and Password credentials are correct
The User must exist on your Database Server

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 60 milliseconds ago. The last packet sent successfully to the server was 55 milliseconds ago.

javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)

UPDATE :

This is from the mysql's error log file, when trying to connect with Unicenta.

    Version: '5.7.36'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL)
2021-11-09T16:39:31.970790Z 2 [Note] Bad handshake
2021-11-09T16:39:31.981642Z 3 [Note] Bad handshake