Hoping that revealing my ignorance might help someone else someday.
I have a new L1, B1, T8S. I noticed that I was getting seemingly random volume loss in Channel 3 (acoustic guitar). I couldn’t figure out whether I had a Bose issue or a guitar issue. Turns out it was a “me” issue.
Apparently, I was occasionally (and unintentionally) powering up my system components in the wrong order.
The set up: My guitar plugs directly into a vocal harmonizer (for key detection), which then sends the unprocessed guitar signal out to the T8S Channel 3. I think I was causing a voltage fluctuation in the T8S when I’d randomly power up the harmonizer AFTER there was power on the T8S. No other channels seemed to be affected, even though the harmonizer vocal goes to a separate mixer channel. I finally got a clue when I heard a faint speaker pop when the harmonizer powered up.
Here’s the power-up order that seems to fix the issue: Pedal Board > T8S > L1. Powering down in the opposite order.
Anyway, here’s to rookie screw-ups! So glad I didn’t call customer support and make a scene. That woulda turned out to be somewhat embarrassing.