Check first to make sure your goal frame is not bent/leaning backwards. Look at your goal from the side. If it’s leaning towards the back of the goal, your Smart Backstop will also lean back. The front of the goal frame needs to be straight/vertical.
If your goal looks good, you can straighten the backstop by adjusting the two corner bracket assemblies.. As with anything that is screwed on, they can sometimes loosen over time. On each side loosen the two “j” bolt clamps and velcro strap, then rotate the corner bracket towards the goal frame. Re-tighten the “J” bolt clamps firmly and fasten the velcro strap. Don’t be afraid to use some muscle when tightening, the clamps won’t strip.