Session Initialization w/.NET API

SOLVED

I have the following code to create a session.

Session s = new Session();
s.Init("", "XY", "XY1000", "67A");
s.Open(User, Password, Company, DateTime.Today, 0);

A client had been using ADMIN/ADMIN for the username and password (don't ask why they never changed the password) This is being used for an integration written in .NET. Everything has been working great for years.

A new administrator has come in and is saying this is not good (agree)

He wants to have a separate user for this application to use for connecting to Sage. A user, WEBAPI, is created and given a password. The account can be used to login to the Sage UI but it fails when the integration application uses it. The only username/password that works is ADMIN/ADMIN.

This was done successfully on a test system.

Why?