This Node + Express application that communicates with databases using the node-firebird library connects to multiple databases, some on a Linux server and others on another. The code was always able to connect to the databases on both servers, in the test environment on my personal computer and in production on the Render platform. However, I recently moved the application to work on the server where some of the databases are located. From there, it can access the databases on the other server, but it cannot connect to the databases on the server itself, returning: