A couple things that might be 'useful information.'

With Realtracks, BIAB can only play a particular chord if the musician recorded that chord by playing it in the parent audio recording for the Realtrack.

It is also possible that, if the chord exists within the Realtrack audio, BIAB is substituting a different chord. By default, BIAB will do this if the program's analysis of the chord progression determines that a better chord exists. To disable this option, under Song Settings and in the Natural Arrangements window, select "Disable natural arrangements for this song". With Natural Arrangements disabled, it is then possible that using "Auto fix sour notes" (set to Chord) will correct the Realtrack note for you.

Matt Finley has written about what to do if the chord is playing something different from what is entered. His article is in the post below. It is worth reading.
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=694482#Post694482

Also.. have you tried Ebaug/C? This might give better voicing than Baug/C. Ebaug/C should place the major 7th note above the minor 3rd (Eb) rather than below it.

MY SONGS...
Audiophile BIAB 2025