I've been working with it for a couple of days to find out exactly when and why it does this.

VideoTrack, I'm using BIAB 2021, with the latest updates as of this post.

So it happens when I change out instruments. I will change an instrument, generate the whole song to listen to it, then when I drag that track to the D&D box, it generates everything again. It's just oddly redundant and time-wasting. I just upgraded my system last week to a Ryzen 5900x, so it doesn't take NEARLY as long as it used to, but it's still a strange waste of time: I LITERALLY just regenerated the entire song. Why are you doing it again, BIAB?