Originally Posted by Keith44
Maybe a return to factory settings would fix the problem.

Keith

Ya, when BIAB does something which it is not supposed to do, it is time for RTFS.

I tried to reproduce what you are reporting. Used same style and chords. Selected "simple arrangement". Certainly no out of key notes (C#). But I did get notes other than triad, (i.e., 2nd and 7th). This is what I would expect.

BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, 1TB WD Black NVMe SSD, 2TB WDC Blue SSD, 1TB WD Blue, 2 TB SK NVMe, 6 TB External, Motu Audio Express 6x6