Operation timed out when call JDBC driver from Oracle java stored procedure

I use 0racle java stored procedure to read data from MS SQL Server and Advantage Database Server via JDBC driver.
There are net.sourceforge.jtds.jdbc.Driver for MS SQL and com.extendedsystems.jdbc.advantage.ADSDriver for ADS.
Java code to create connection

public static Connection getConnection(String JDBC_Driver, String JDBC_URL,

                                       String userName, String password, Connection pompa) throws ClassNotFoundException, SQLException, java.util.ServiceConfigurationError, UnsupportedEncodingException {

    Class.forName(JDBC_Driver);

	try {

		String connectionURL = JDBC_URL;

		Connection conn = DriverManager.getConnection(connectionURL, userName,

			return conn;

		}

	catch (Exception e) {

		return null;

	}

}

It works fine with Oracle Database 12(Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production) and 19. I(Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - ProductionVersion 19.18.0.0.0). Java stored procedure creates connection, gets resultset from target database and returns it as json back to Oracle database.