I'm running Windows 10 (Education) 15063 and I've had a strange issue that didn't occur under Windows 8.1. Seemingly randomly, the upper volume limit drops. This usually occurs when switching from speakers to headphones by plugging them in. This means that setting the volume control to 100% results in quiet sound output in this "post-error" state. Restarting the computer or restarting the Windows audio service fixes the issue.

A concurrent issue is that when software takes exclusive control (such as Foobar2000) via WASAPI in this "post-error" state, changing the volume doesn't have an effect on the volume of sound. In normal situations, exclusive mode volume is controlled as regular by the volume mixer.

I have gone through everything I can possibly think of. I've tried all the drivers available. I've tried disabling every sound device except speakers and headphones. I've tried disabling the VOIP volume reduction option. What am I missing?