I'm guessing, but AIUI Radio (and TV) Jamming is done on targetted frequencies because a wide spectrum Jammer would simply require too much power ... I suspect the current problem is that a lot of drones are commercial, and use the same narrow band of frequencies, and that even the militarised ones do as well.
I suppose that Drones could be equipped to do Frequency Hopping, but that would, presumably, add to their cost to some degree.