Why can't I capture Netflix audio with my Chrome extension tabCapture method?

Question

My extension captures tab audio (still using manifest V2) with the tabCapture method. It seems to work well on every site I've tried, other than Netflix. To be more specific, it works when previewing videos on Netflix, but not when the actual player runs the video. The stream itself is captured and returned in the callback, and there is no other error I could find.

const constraints = {
  audio: true,
  video: false,
};

chrome.tabCapture.capture(constraints, (stream) => {
  if (stream) {
   //do something
  }
});