SUMMARY
When in the Media Control menu, there is a volume slider. When it is dragged to find the right volume, the new value is sent only when the slider is released. This behavior is weird, a quick fix would be that when pressed, a live update of volume is sent to the server every X milliseconds (100ms is great). When released, the slider sends its final position to the server (if different from the last).

STEPS TO REPRODUCE
1. Connect PC and phone together.
2. Launch some media on the PC.
3. Go on your phone, open media controls, and drag the volume slider.

OBSERVED RESULT
Volume is sent only when the slider is released.

EXPECTED RESULT
Volume of the media should change accordingly, without releasing the slider.

SOFTWARE/OS VERSIONS
All latest (Manjaro + Gnome + GSConnect (ik, this is not KDEConnect but it shouldn't cause any problems as it is client-related) )

ADDITIONAL INFORMATION
As seen in Gitlab, / src / org / kde / kdeconnect / Plugins / SystemVolumePlugin / SystemVolumeFragment.java has a function called "updateSink". A comment is expliciting that volume changes should not be sent until the slider is released. Maybe by inverting the functionality : if the slider has moved X ms after the last update, send the new position to the server.