Settings -> Audio: Disable everything you don't use.
That's good practice anyway. Don't have things hanging around that you don't use, because they can only hurt you.
Default settings are nice to get you going, but that's ALL they're good for. As soon as you can, look through all of the settings, figure out what they do, and set them all, on purpose, to suit your purpose. It might take a while to wrap your mind around some of them, but the sooner you do, the better you'll be.
That applies to everything, not just OBS: Windows, other apps, physical gear, etc.
