Moto G6 audio sending through wrong audio channel My unrooted, basically stock android decided to stop sending audio through any channels except call audio today. I have not installed any new or unstable apps recently. Symptoms include:


the lower speakers (the ones used for playing music, etc.) are completely nonfunctional. 
The upper speaker sounds like I'm in a call all the time. When I am actually in a call, it is nearly silent unless I'm on speakerphone, at which point it's as quiet as any other app.


I have attempted general troubleshooting. To wit, this includes:


I closed all current apps and then tested sound. No change.
I rebooted the device. No change.
I booted into 'Safe Mode.' Problem persisted. 
Connection over Bluetooth seems to be immune to the issue. I connected a headset and nearly blew out my right eardrum. 


Any suggestions on what the heck is going on and/or how to fix it? 

Update:

Appears it was a hardware issue, as it spontaneously corrected itself a few days later.
So basically, I waited for a few days and it fixed itself in the middle of the night. I don't know why. Sorry, future humans! 

Given that it both spontaneously started and stopped, that it persisted through multiple restarts, and that it was present during safe mode, I suspect that this was either a hardware issue or it was embedded in the registry. 

note to editors: this answer is here simply to successfully close the question.