More information is necessary to help you.

First. If you replace your UserTrack with a RealTrack, BIAB will use the RealTrack, not your UserTrack. I assume BIAB will use the waveform format of the RealTrack, not the UserTrack.

Second. BIAB can't generate new material for your UserTrack regardless if it's recorded in Stereo or Mono.

Stereo to mono and and mono to stereo function is available in the Edit menu of the Audio Edit Window. I don't believe with the information known so far that waveform conversion is the root issue.


BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.