MySQL Keeps Down (Cpanel Server)

I have a Cpanel server with a problem: SQL keeps failing

Everytime I try to restart MySQL via WHM, it gives me:

/usr/bin/mysqladmin: connect to server at 'localhost' failed error: 'Can't
connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock'
exists! mysql has failed, please contact the sysadmin (result was "mysql
has failed").

I can only restart it successfully after 2nd attempt. Server load is always low. Memory usage is also low.

It happens in very short interval (in less than every 1-10 minutes)

It never happens until recently when my server management company tweak something I didn't know. They said fixed it and then it happens again every minutes.

I have 9 servers and it never happens to the rest 8 servers. Just this server always happening.