Yeah, Jeff, thanks for raising this concern. I will definitely pay attention to this.
I believe this can be fixed, but cannot give you any guarantees until I try it out.
Firstly hello, (first post) I seem to be having the same problem, I bought my BB yesterday online (UK) and right out the box this problem with the headphone volume window pops up during a drum set, I think that’s the right phrase, I only started tinkering with a guitar at xmas after been told by my doctor it will help with my Alzheimer’s, could not get on with a metronome so bought a BB, sorry I digress after trying different leads etc, I found the problem went away if I left the headphone volume control at above 30% (makes no difference to the sound coming out of the amp) my question is why are you not returning your BB for a replacement?