While I generally agree with this it feels wrong in this case since everyone who bought it can get a refund.

It looks like a fan header with a molex split. But more pictures would be needed to confirm 100% (A picture of where the cable connects to the motherboard in particular)

I assume it is a fan with both a 4pin header and molex like https://ae01.alicdn.com/kf/HTB1bjiuX5frK1RjSspbq6A4pFXaS/120mm-LED-Ultra-Silent-Computer-PC-Case-Fan-15-LEDs-12V-With-Rubber-Quiet-Molex-Connector.jpg You would only connect one of the ends and the other end would be left disconnected.

My guess is that the molex end was never connected to anything and was simply tucked under the IO shield to the left or the VRM heat sink above. It was probably jostled loose during transport. You can take a look around for anything with the same size as the loose connector to see if something was plugged in there. The connector is shaped like the letter “D” where one side is flat and the other has slightly rounded corners so you can only plug it in one way. This cable is for power only so it would probably be something like a fan or a light.

If I am correct then the cable can be left unplugged and you can tuck it somewhere to hide it or just leave it taped. It would also be unrelated to your headphone issue.

I blocked the notification with uBlock and just pretend nobody ever reads or comments on my comments. You can say whatever you want if nobody is around to hear it.

Not having a global karma score that is require to post in different subreddits helps too.

Games would go on sale for example 50% off and people would buy them. Then they would have a flash sale for 90% off. People who bought the game for 50% off then refunded and bought it at 90% off. This resulted in lots of refunds steam had to process. Since they couldn’t get rid of refunding games they got rid of flash sales.