This is still a bug in Xcode 12.5 on macOS 11.4. Have had to kill the CoreAudio daemon multiple times per day for nearly a year now. The simulator audio output control is new to me, have it set to an unused output when I don't need audio from simulator. Hopefully it holds. Thanks @Choonghee for the tip!

Fantastic workaround from @malc that doesn't require importing AppKit. Kudos!

Also having this issue. MacBook Pro (15-inch, 2019) on Big Sur 11.0.1 (20B28)/Xcode 12.2 (12B45b). I'd be shocked if Apple hasn't observed this internally. I opened a feedback request for this, FB8939085.