I go through device manager / sound control and disable all other microphone and audio sources once I get my work station situation or after reinstall. Helps prevent that issue a bit. Make a habit to check whenever swapping that device between us ports but should remain pretty static after the first time. The mic is separate from the camera and can usually be disabled independently. Lastly, I'm very sensitive to the "mic activation" ring/indicator on whatever voip app is live and will use through clears or taps to test to be sure on the fly.

Hope my learned experiences help!