Mac Book Pro 2019
Sonoma 14.7.8
BIAB 2025 (902)

I posted this issue in another thread, but it also suits this one, since it deals with a likely bug in BIAB 2025 for Mac:
Mi BIAB has total access to the disk and all the permissions.
The issue is with midi sounds since the moment I used the Medley option, thus:
Track settings and actions dialog / Medley / Change to a new Real Tracks every / 8 bars / OK / Play.
Everything sounded as expected, but from that moment on, the GM sounds are behaving crazy: when I play back a MGU file with midi sounds, the piano plays the percussion part, and the other instruments are either silent or holding all the time a single note. This aplies to both new and old MGU files.
If I save a MGU file as a MIDI file, and play it back with a midi player, it sounds fine, but not when played back from within BIAB: even the audible lead-in instrument is a piano, instead of the expected default side stick.
I would appreciate any help to solve this issue.
Luis