Fuel pump relay keeps burning one prong and getting super hot

No accidents no damage and no recent repairs. The only thing that was changed was a little box was plugged into the obd-2 port for insurance purposes and then started causing the issue and burnt up the fuel pump relay. The box has since been unplugged and left out. The only three things I could narrow down to is the ecu,fuel pump or fuse block. All are around $200 each. My thought was that the fuel pump shouldn’t have 14v going to it and since it does it’s causing the relay to get super hot and burn out

I must add that the car was purchased 2 years ago from a dealer and only has 68263 on the odo.