Xbox Game Audio loops into microphone source

So I have recently put together a set up for recording my Xbox gameplay to edit and mess around with. I have an Elgato HD60S+ that takes the HDMI from my xbox and records onto my PC while displaying it to my monitor to play. I use an Astro A40 with the MixAmp Pro to listen and talk with friends, so I wanted to record my audio as well in a separate track. I plugged a 4 pole 3.5mm cable into the 'stream' output cable (which some research shows is what everyone uses to record microphone audio) and the other end into the back of my PC inline.

It shows up as a separate source and picks up my voice just fine, the one issue is it also constantly sends through my game audio in that channel as well. To my understanding the 'Stream' port is meant to only output my voice. If anyone has experience with this problem, or knows where to look better than me I'd love the help.