It appears that features on an
ol.layer.Vector are not painted or drawn during panning animations or mouse-drag events (in OpenLayers v.3.1.1) Does anyone have a work-around?
To see the problem, take a look at: http://jsfiddle.net/StephenM/489aveLr/6/
If you zoom in on the rectangle covering Antarctica and use the mouse to pan around, you will see that the rectangle is only painted after the mouse button is release and the pan-animation has completed, whichever happens last.
I found some references to this behaviour in older versions of OpenLayers but it was apparently fixed in version 2, already. Why am I seeing it here? I have tested in Internet Explorer and both Chrome and Firefox and the behaviour is the same.