I know of one occasion in Asia where a Supa Puma, flying to a rig some 140 miles out found there was nothing there when the GPS said there should be.
The GPS had junped somewhere and they had to turn back to land. Not enough fuel so they had to ditch, successfully, without any injuries by a couple of fishing boats. The aircarft conveniently sank in deepish water so they could not investigate it.
If they had checked that their NDB was pointing in the right direction on departure they would not have gone the wrong way.