engine model size error-yolov5

[phhh-xh]

Thank you very much for your work, I replaced the pt file of the yolov5 model with the engine file, made the block prediction, and reported the error

But the size I exported is 640640

The size of the image I sliced is 640640, I can't figure out why, you have done some processing on the dimensions of the image？, looking forward to your reply