This is based on the latest Mapbox GL JS (v0.25.1). I've posted a demo repo which has one file (index.html) which when loaded in Chrome fully replicates the issue. That file is an almost complete replica of: https://www.mapbox.com/mapbox-gl-js/example/drag-a-point/

The only differences are the places where map.dragPan.enable() and map.dragPan.disable() are called. Instead of calling those functions during mousemove, I call them during mouseup and mousedown, but that should work fine too...

Repro file at: https://github.com/ntilwalli/mapboxDragPanIssue

Steps to Trigger Behavior

1. Load the index.html file from the repo
2. Try dragging the circle (it won't work)
3. Try dragging a second time (it will work)

Expected Behavior

Dragging circle should always work

Actual Behavior

Dragging circle only works from second attempt onwards