FoxThe Problem Some Bluetooth headsets (or from my limited experience, all of them) handle...
Some Bluetooth headsets (or from my limited experience, all of them) handle Play-Pause behaviour internally instead of relying on the OS to tell whether media is playing or not. This can easily lead to a de-sync between the host and the device, where the device will either end up constantly trying to Play while media is playing, or Pause while media is paused.
This can be verified by running xev (sorry Wayland users, get gud :p) with and without media playing, then seeing if eventually the wrong signals are sent (XF86AudioPlay when the device is supposed to pause or XF86AudioPause when it's supposed to play).
It is worth mentioning that this issue does not occur on Android, I wasn't able to manually verify the reason myself as it was too complex for me to look into, but investigating with Google Gemini reveals that Android has a way to communicate with Bluetooth devices to sync playback state.
The solution is to redirect both XF86AudioPause & XF86AudioPlay to XF86AudioPlayPause, bypassing the whole internal state issue, this is most easily done through your Desktop Environment's shortcut settings.
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