The new Corpus Ship tileset's reactor has, apparently, two slots where the fuel/coolant cells can be introduced. However, when we interact with the one that's market for the reinsertion of the cell, the animation doesn't actually show the cell going into it. The cell simply appears in the *other* slot on the other side of the reactor. Here is a video explaining what I mean. I this one I am reinserting the fuel cell into the reactor.
As you can see, it doesn't go into the right slot. It goes into the other one.