This results in 2 USB cables. What's happening is the USB cable is supposed to be at the end of the book maze, but for people that already went through the book maze it appears in the entry (as seen in the screenshot). So depending on what you did in the last version you will either find the USB cable at the entry to the building or at the end of the book maze. Same with the heart container. Above the entry if you've already been through the maze, inside the maze if you haven't.
Interesting. I had already been to the maze, but even then, the cable didn't appear at the entrance, it just didn't show up anywhere, until I unchecked the switch. It wasn't in my inventory either.
After that, the cable appeared at the entrance and the game just progressed. There was no second cable or duplicate, because I didn't change any variables, just unchecked the switch.
Now, I loaded an even earlier save, before I could move the boxes and went to the maze
only after I got Amber's phone. That's when the cable appeared there.
Maybe going to the maze earlier at a certain point, made the game think I had already gotten the cable and checked that switch, when I didn't actually have it in my inventory and caused this problem. So I suggest only going to the maze for the first time, after getting the phone.