I get that sometimes. I thought it was Bluetooth having trouble. If I turn the phone upside down in my pocket, or switch which pocket my phone is in, it’s often fixed.
This is with hearing aids and several different earbuds; and has followed me between iPhones, so I’m at a loss to explain it.
Ah damnit. I sorta thought this problem started on my old computer but I thought ‘Surely not. How could this problem be tied to my Apple ID??’ but your experience suggests I was correct. :/ was hoping it would eventually go away with a new device
This really threw me for a loop before I figured out what was happening because I assumed I had dodgy connections somewhere.
In the end I had to get a piece of software called 'Balance Lock'. It's not FOSS but it is free and according the app store doesn't collect data. It also has no ads or in-app purchases. I'm pretty happy with it so far. It does one thing and one thing well and that is to keep your audio balance at a chosen setting and shift it right back there again whenever that balance slider likes to go for a little walk. Weirdest issue, apparently been around for years.
Is this on macOS? I‘ve had a similar problem for a while. The balance in fact sometimes changes itself.
With the following terminal command you can reset the balance in case it gets shifted. Make sure your headphones are connected and selected as output device. osascript -e "set volume output volume (output volume of (get volume settings))"
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