It goes into the port. I had the same issue and DJI said push it back into the port and pull some of the cable out for more slack. It's a bitch to push back in though..
Yes the empty port is the correct (I took a pic but it won't load on forum today don't know why)? I put a rubber tube over both the wires leading into this area to keep them together and to stop them wearing against the chassis of the craft.
Even once I push it back in it fits loosely. Likely a manufacturing flaw. I might try running a ziptie over all of the cables to keep them from moving.