Thruster Components Appearing From Nowhere

I created a ship on the Earthlike planet and put some Ion Thrusters on it even though I had no source of platinum. I welded them up to everything except the Thruster Components and planned on adding them later when I acquired some platinum. I saved and exited the game and went to lunch. When I reloaded the game later I saw that all of the Ion Thrusters now had Thruster Components in them ready to be welded to completion. I had no way to make them since I had no source of platinum so I know I didn't add them myself. Something about saving and reloading the game made the Thruster Components appear from nowhere in the Ion Thrusters that were on the ship. Here is the save file. Look at the Ion Thrusters on the ship I'm standing on. They all have Thruster Components in them that weren't there before I saved and reloaded.

To reproduce just make a small Ion Thruster and weld it up with everything except the Thruster Component. Save and reload the game and the Thruster component will magically appear in the Ion Thruster from nowhere.

Edit: Oh it's a single player offline world and I'm not using any mods and the version is the default 1.193.021