With the latest Leaflet (Leaflet 1.9.2) dragging the control is not working correctly. The map itself is being dragged. There is a simple fix. Add:
L.DomEvent.disableClickPropagation(this._container);
To the addTo function (I'm calling it right before the return this). This disables propagation of click events through to the map.

Optionally, the functions cancelMapDrag and uncancelMapDrag are not serving any purpose, and they (and the event hooks to them) can be removed.

I have no idea what Leaflet version this first started manifesting with.