It's worthwhile double-checking the auto-substitute possibility just to ascertain that it is not causing the issue.

To do this, go to Realtrack preferences and disable the two auto-sub options that I've highlighted below. Press 'OK' to get back to the main screen.



To make sure that these changes are activated in preferences, exit and restart BIAB. Next load your song, go into RT prefs and doublecheck that the preferences are still deselected. Now try loading the RTs you want to add. Is the behaviour still the same?

It's always possible to tell when auto-substitute is in play because a substituted RT's name in the mixer will begin with ~ (see image below where the bass RT has been substituted).



Let us know how you go.


MY SONGS...
Audiophile BIAB 2025