I'm going to guess corrupted BiaB files are to blame. Rare, but it happens. Like you, I prefer to understand WHY something is happening so that it doesn't happen again. But in this case, I'd simply recreate the the practice tracks from scratch. Couldn't take more than a few minutes to see if this resolves the issue.

It doesn't sound like a patch is warranted, but I may be missing something...


DC Ron
BiaB Audiophile
Presonus Studio One
ASUS I9-12900K DAW, 32 GB RAM
Presonus Faderport 16
Too many guitars (is that a thing?)