AWS Lambda node.js ETIMEDOUT when accessing MySQL or MS SQL in RDS

I am trying to a connect a AWS Lambda function to a database in RDS, I followed a few posts that have suggested they both need to be inside the same VPC, but have been told by Amazon support that this is not the case. Although I have tried a multi subnet VPC with nat gateway and security groups allowing access to each, with no prevail.

I am able to talk to the Database instances in SQL management studio or MySQL workbench without a problem.

10:13:00 2017-05-16T10:13:00.509Z Callback connection.connect() 10:13:00 2017-05-16T10:13:00.547Z Error ETIMEDOUT

I have tried a few different methods of connection now, I used an example as seen in the post, the only difference is this databases wasn't in RDS.

Querying a MySQL database from a NodeJS AWS Lambda Function

I have tried a MSSQL and MSSQL databases instances, both experiences a timeout on connection. I have attached all relevant policy's to the lambda function.

I have included below one of my simple tests, just to try and get a connection.

Test Code added below, not this at the bottom of a alexa call.

function mysqltest2() {
    var mysql      = require('mysql');
    var connection = mysql.createConnection({
      host     : 'endpoint.rds.amazonaws.com',
      user     : 'user',
      password : 'pass',
      database : 'db'
      });
                  var test;
                  console.log(`Intent Request`);
                  console.log('Then run MySQL code:');
                  connection.connect(function(err) {
                      console.log('Inside connection.connect() callback');
                      if (!err) {
                          console.log("Database is connected ... ");
                          connection.query("SELECT 1 + 1 AS solution",
                              function(err, result) {
                                  console.log("Inside connection.query() callback")
                                  if (!err) {
                                      console.log(result);
                                      console.log("Query Successful! Ending Connection.");
                                      test = result;
                                      connection.end();
                            } else {
                                      console.log("Query error!");
                                  }
                              });
                      } else {
                          console.log("Error connecting database ..." +             err.message);
                      }
                  });
                  return test;
  }