In my case, there was an error in log:
190122 4:39:09 [Warning] mysql.user table is not updated to new password format; Disabling new password usage until mysql_fix_privilege_tables is run
The mysql_fix_privilege_tables was replaced with mysql_upgrade in MySQL 5.1.
For my Mariadb 5.5 I ran to fix it:
mysql_upgrade --force
And restarted the service.
