[originalscottyg]

Using the New Track method of routing to an Aux always creates a new bus in the process. Since you are using Last Used for your I/O Settings, you probably (definitely) already had a bus called overheads. Pro Tools can't have 2 busses named exactly the same things, so it calls the new one overheads.1.

You could start from a template that already has all of your tracks and auxes setup and properly routed. You can have multiple templates for different setups.

You can have a single template session containing every possible iteration of tracks and scenarios and import only the session data that you need into your new blank session (this is what I do).

You can start with a default I/O setup (e.g. Stereo Mix) instead of Last Used. Then when you use New Track to create a new aux and bus, it won't be a duplicate.

Or you can keep using Last Used when you make a new session and create the aux and route the tracks manually to the already existing overheads bus, without using the New Track method.

As somebody on the DUC once said "The good thing about Pro Tools is there's 4 ways to do everything. The bad thing about Pro Tools is there's 4 ways to do everything."