From the factory it comes with a foot long plastic strap connecting that cover to the pillar to prevent just this. All four door connector covers have this strap. Yours is probably lost or it may just have gotten detached from the cover but may still be attached to the pillar. If the latter is true, you can reattach that strap to the cover so when you remove the cover to unplug the door connector, the cover will remain tethered.