When out of my FOV, idle artifact extractors (and construction drones for that matter) seem to continuously rise upwards off the ground, way above the camera's height limit. Using another extractor to try and regroup the others indicates that the missing extractors are still within XY range, but they're so far off the ground they're basically inaccessible at this point. When the extractors are within loading range, they seem to start descending again, but 78 of them are now missing from the excavation pit.
Boat enjoyer
yep sometimes they come back the rest double as communication satalights lol