I NEED HELP ASAP

I agree with Francesca Knowles, check the coupler adjustment. There is a nut up inside that adjusts how far the clamp inside the coupler moves when you latch it. Too tight and you can't move the latch all the way, too loose and it will not clamp tight enough when latched. I remember having to adjust the one on my old pop-up when I bought it. I would be surprised if it was that loose as to allow it to pop off the ball, but it is possible. And when you eliminate the impossible, whatever remains, no matter how improbable, must be the truth :)