Output Devices Suddenly Merged Into One

[Windows 10 Home v. 10.0.19043]



I built this PC a few months ago and its audio devices have been behaving themselves just fine up until today. It's a typical setup - a pair of speakers are plugged into the motherboard at the back, and a pair of headphones and a mic into the case at the front, all by 3.5mm jack. Using the default Realtek High Definition Audio drivers, Windows has always recognised these correctly, and I've been able to switch between them easily from the taskbar icon.

However, this morning, with no clear reason, the heaphones device suddenly disappeared, leaving only the Speakers device, with no option to switch to another. Even more confusingly, while using this Speakers device, by default, all sound goes to my headphones. If I unplug them, the sound is sent to the speakers, then it goes back to the headphones when I plug them back in again. The audio device is still labelled as "Speakers" regardless.

I did nothing to prompt this change - I was just playing Star Citizen and watching things on YouTube. There was no Windows or driver update, I installed no new software, nothing. Just... suddenly only one audio device.

Attempting to troubleshoot/fix this issue, I've unplugged both the headphones and speakers and plugged them back in, tried several restarts, checked for Windows and driver updates - everything is already up-to-date - checked the Realtek High Definition Audio device is still there in Device Manager - it is - and run Windows' sound problems troubleshooter - which, of course, solved nothing.

Anyone know what's happened and how to fix it? I just want Windows to recognise that my headphones and speakers are separate devices again, so that I can switch between them without having to unplug them.

I'm wondering if someone has a solution to this, I'm having the same issue: only the Speakers (Realtek High Definition Audio) device is displayed and my headphones are gone as well.
The properties show this single audio devices uses both the rear and front panel jacks.

Having spent a day putting up with this, I can confirm it's even more annoying than it might at first appear. When headphones are plugged in at the front, it doesn't actually consider them the primary playback device - at least, that's my interpretation - as whenever a sound plays after a period of silence, there's an audible crackle as the PC hastily switches to sending sound to the headphones, rather than keeping that channel open continuously. Sometimes these crackles are uncomfortably loud.