Lower left hot corner problem.

Problem when returning to desktop. I click on windows 9 start screen link  on desktop start menu and I am taken to the start screen. After working in that environment I click on the lower left hot corner to return to the desktop and on return find the start menu is still open and have to click on the screen to close it. If however, I return to the desktop using the upper left hot corner the start menu is closed as it should be. Very annoying.