Rear Hatch opening problem

I have a 2014 Impreza 2.0 Hatchback and the rear hatch no longer pops up to a fully open position. When I press the open button the hatch only opens slightly and I need to manually open it completely. This is kind of a pain as this process is under some kind of pressure so it takes some effort. Has anyone had this problem and can you share how you resolved it?