Reinitializing the liftgate

Q: I have a 2014 Toyota Highlander and I'm experiencing an issue with the automatic rear liftgate. Last week, while the car was parked in the garage with the door closed, I accidentally hit the liftgate open button on my key fob. The liftgate opened but hit the closed garage door and then stopped. When I pressed the button again, it closed properly. However, since that incident, the liftgate only opens partially, and I have to manually lift it to reach the full height. It closes perfectly fine when I press the button. What could be causing this problem?