I click 'exit case' and it doesn't grade the case!

This is a misunderstanding of how the program works. When you hit "exit case" this will save your work and is for convenience if you are not able to finish the case right away. If you want the case to end, you need to advance the clock until the case ends. Clicking "exit case" will not end the case. It means you are prematurely leaving the case, but in the online/web version, it will save your work, so you can return and start off from where you started.