Additional meeting and call-related features and issues within Microsoft Teams for business
I've found by turning off the "new meeting experience" within the Teams settings allows for audio in meetings. So it's not exactly a fix but a workaround by removing an included feature that may be turned on by default.
It's definitely an issue with the app itself and not with audio drivers, usb peripherals (like headsets), or anything outside of Teams. What I suspect is happening is when Teams creates the meeting in a new window, it doesn't transfer or enable audio output to the new window.