Affected versions

• Ubuntu 22.04
• Windows 10
• Mac M1

Affected platforms

• Firefox 100.0.2
• Nightly102.0a1
• Firefox 101.0b9
• Firefox 91.9.1esr

Steps to reproduce

1. Launch Firefox and go to www.pinterest.com where you log in
2. Click on any video longer than 45s(where PiP toggle is available)
3. Open the video in Pip
4. Click PLAY on the origin player(video was paused automatically on step 3)
5. Close the PiP window

Expected result

• When opening a video in PiP while is being played back, the video should continue to play in PiP window.
  When closing the PiP window of a played back video, the video should be paused in the origin player.

Actual Result

• When opening the video in PiP, it is paused in PiP window. After it is played back manually and we close the PiP window, the video continues to play back in the origin player.

Regression range
This is not a recent regression.

:epopescu, if you think that's a regression, could you try to find a regression range using for example mozregression?

I can no longer reproduce this issue in the latest Firefox 121.0.1 on Windows 10 x64.
Marking this as WORKSFORME.