We make a product that records the user's screen from the browser, using navigator.mediaDevices.getDisplayMedia ; it works nicely everywhere but we face 1 issue for 1 client, and I was wondering if anyone had this issue before: with Chrome browser (99.0.4844.83) on MacOS (Monterey) the screen recording ends up with a dark blank screen video with no apparent reason.

We even sent him to this online testing tool for webRTC recording, and the result is the same: a dark video.

There is no permission error, there is only one screen on the computer and one video stream, and the resulting video file has 1 video track with the proper screen size, and the correct duration. Plus, during the recording we can see the video stream correctly mirrored into a video element that shows the correct video stream.

But at the end, when the browser put the resulting blob in a video file, this one is just blank, like a stale dark rectangle, and we can't figure out why? Any clue?