I've got 2 SQL Server databases hosted in Amazon's RDS system to power 2 copies of the same project.
They've got identical database names, identical passwords, identical security groups applied and are configured in build process.
Once built and hosted on elastic beanstalk both instances of the app work and can talk to their database.
However I can only connect to 1 of them with SQL Server Management Studio from my public IP.
Even if I open port 1433 to EVERYONE 0.0.0.0/0 I'm still unable to connect to the 2nd database.