Depends on whats going on around the areas where the saboteurs spawn. I know that the all locations tend to have Public events happen on the location or very near by which could take precedent. I would recommend either jumping between the EDZ Gulch and Nessus Artefacts Edge and see if the saboteur has spawned. Each load should have a different instance of the location. That or chill at one location til one spawns but that can take some time and Artefacts Edge is probably the best for the wait as the location where the saboteur spawns has no hostile spawns in the immediate area if you sit at the fast travel point or on the ship.