I use JetAudio, and I have tried reconnecting/switching power while connected. My Mojo used to work before with the same phone and cable, so it's certainly not my phone (well, I do run Android O beta so unless its internals have changed recently - can't know for sure until Monday with the official Android O drop from Google). I haven't had opportunities to test with other phones - might try next week at work. One thing is that when charging, sometimes there is this weird hissing sound and I have to remove the USB cable. This happened since when I first got the Mojo, so I'm feeling this might be a defective unit.
The other thing is I usually place the Mojo on bed while sleeping listening to music, and sometimes lay on it so I don't know if the buttons were pressed in any weird order/combinations. Other than that, the unit might just as well be too hot and burned?