Oracle connection timeout inside a Azure Function that cancels at 5mins

I have the following lines of code inside a Java function:

    try{

        context.getLogger().info("Paso001");
        Class.forName("oracle.jdbc.driver.OracleDriver"); 

        context.getLogger().info("Paso002");
        Connection conn = DriverManager.getConnection(
        params.get().getConnection(), params.get().getUser(), params.get().getPassword());

        if (conn != null) {
            context.getLogger().info("Connected to the database!");
        } else {
            context.getLogger().log(Level.SEVERE, "No connection to the database!");
            return request.createResponseBuilder(HttpStatus.INTERNAL_SERVER_ERROR).body("Error").build();
        } 
        
        context.getLogger().info("Paso003");
        PreparedStatement sentencia = conn.prepareStatement(params.get().getSentence());
        int index = 0;
        for (Param param : params.get().getParams()) {
            index++;
            if (param.getType().equals("String")) {
                sentencia.setString(index, param.getValue());
            } else {
                sentencia.setInt(index, Integer.parseInt(param.getValue()));
            }
        }
        ResultSet rs=sentencia.executeQuery();

        JSONArray result = JsonHelper.recordList2Json(rs);

        context.getLogger().info(result.toString());
        return request.createResponseBuilder(HttpStatus.OK).body(result.toString()).build();                
    } catch(Exception e)
    { 
        context.getLogger().info("Paso00-err");
        context.getLogger().log(Level.SEVERE, e.toString());
    }

Loging only shows "Paso001" and "Paso002" but connection fails at 300000 ms (5 minutes) because no "Paso00-err" is shown in the logs. I assume that Azure Function is reaching maximum time.

Azure Function is inside a VNET integration and DATABASE is inside another local NET behind an ExpressRoute. I have assumed that Firewall is correct because opening socket to Host:Port inside the funcion seems ok:

  InetAddress IPv4 = null;
  try {
      IPv4 = InetAddress.getByName(connect.get().getHost());
  } catch (UnknownHostException e) {
      result = e.toString();
      e.printStackTrace();
      return request.createResponseBuilder(HttpStatus.OK).body(result.toString()).build();
  }


  try {
      Socket s = new Socket(IPv4, Integer.parseInt(connect.get().getPort()));
      result = "Server is listening on port " + connect.get().getPort()+ " of " + connect.get().getHost();
      context.getLogger().info(result);
      s.close();
  }
      catch (IOException ex) {
      // The remote host is not listening on this port
      result = "Server is not listening on port " + connect.get().getPort()+ " of " + connect.get().getHost();
      context.getLogger().info(result);
  }

Result gets: "Server is listening on port port of host host

Note. I get same error pointing to a public database installed locally.

Is there anything else missing to open? Any ideas?

Edit: I have rewritten code with .NET CORE 3.11...

        using (OracleCommand cmd = con.CreateCommand())
        {
            try
            {
                log.LogInformation("step001");
                con.Open();
                log.LogInformation("step002");
                cmd.BindByName = true;
                cmd.CommandText = sentence;
                OracleDataReader reader = cmd.ExecuteReader();
                log.LogInformation("step003");
                return new OkObjectResult(reader2Json(reader));
            }
            catch (Exception ex)
            {
                return new OkObjectResult("Error: "+ex.ToString());
            }
        }

and similar results but this time exception is going thrown:

Error: Oracle.ManagedDataAccess.Client.OracleException (0x80004005): Connection request timed out
   at OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword, OracleConnection connRefForCriteria)
   at Oracle.ManagedDataAccess.Client.OracleConnection.Open()
   at Oracli2.Function1.Run(HttpRequest req, ILogger log) in C:\proy\vscode\dot2\Oracli2\Oracli2\Function1.cs:line 50