Remove or revoke DB access or privileges from mysql user both local and remote:
REVOKE ALL PRIVILEGES ON *.* FROM 'plugins_dbuser'@'localhost'; REVOKE ALL PRIVILEGES ON *.* FROM 'plugins_dbuser'@'%';
REVOKE ALL PRIVILEGES ON *.* FROM 'plugins_dbuser'@'localhost';
REVOKE ALL PRIVILEGES ON *.* FROM 'plugins_dbuser'@'%';