They ARE already removed from your network because they are not in the list (just like 2, 4-6, 10-13 and so on). I suspect they are (and stay) in the paths because they were actually really used when they were active.
Since the nodes that used them became marked “unknown” in the mean time, the “ghost nodes” will keep showing there until you either delete the “unknown” marked nodes or activate the corresponding devices.
