I can't have my Mic and headphone cable both plugged in at the same time, when I plug my headphone jack in it "unplugs" the Mic jack and then no mic is found in the device manager. Both the headphones and Mic work fine on their own though.
Need some details about what this headset is and how you are connecting it, are you using a single combo jack on a computer with an adapter, dual jacks, has this always worked, if not what happened before the issue started, etc... List all the details and what you tried already if anything.