'Streaming from my Nintendo Switch'? That makes it sound like you're using OBS on your Switch!
So from your logs it looks like you're capturing the Nintendo Switch with an Elgato HD 60S feeding into OBS, and you're capturing your voice with some kind of mic via your computer's built-in Line-In port. But... you didn't mention how you're talking to your friend? Is he in the same room as you? Are you talking with each other online? Does Minecraft have a built-in native voice chat (I'm not super familiar with Minecraft)? You mention the Xbox Companion App, are either of you using an Xbox?
Since there aren't many details you provided, so I'll just start off recommending that you use Discord instead of the Xbox app (or any other app) if you're talking online together, it's the most common gaming voice application and it's very robust. It's also very easy to set up and it is easily captured and incorporated into OBS. There are even Discord overlays to show who is talking if you want that.
But please provide some more details about your situation and setup so myself and others can provide better advice!
