Ghost Drone, Materials, and Fabricators.

[Tewf]

Ghost drones are able to pick up and seemingly insert materials to refill fabricators as seen here

Drone OMB-27 begins quickly stuffing materials into Reverse-Engineering Fabricator!
You finish stuffing materials into Reverse-Engineering Fabricator!
The magtractor deactivates its magnetic field and lets the mauxite bar fall to the floor.

However, the materials dont go up and the bar never leaves your magtractor.
I tested it about 3-4 times, same result every time.

[MrMagolor]

You have to clickdrag the materials into the fabricator.

I should add that it's impossible for ghost drones to use the nano-fabricator - says you can't insert materials because "the item is attached to you".