This is happening more and more I got stuck under a bush on Piazza a couple of nights ago, I dropped down to reload on the edge of the Dropzone for cover and couldn't move for a couple of minutes so I had to quit the game.
It's happened to me on Bootleg as well I got stuck in a corner while holding the zone but couldn't move because of an explosive care package.
It just seems that the Dropzone game mode is affected this way whatever the map.