Stereo is acting up this morning. Nothing out of the left channel. Muscled the speaker away from the wall and checked the connections, no problem.
Then (what should have been before that), I swapped the channels on the source, and sure enough the problem moved to the other speaker. Checked all the connections all the way back to the USB plug into my laptop, and all of the balance settings. Nothing.
Open up YouTube. Sounds fine. Switch my audio player to my desk speakers. Sounds fine.
The left channel from one app is not going out to this one device, but works ok with other devices, and with that app on other outputs.
I'm baffled.