Did you get stuck while doing a presentation to a large group of people and all of a sudden your powerpoint stops and your audience can’t see the slide anymore? Well that has been happening to my professor and I had to find a way to resolve it. This occurs because the screen resolution while presenting is set to automatic.
The way to resolve that is to go the slideshow tab and then click on use current resolution, which should resolve the problem if you have having the slideshow mode turning off on the secondary monitor during the middle of a presentation automatically.
You can see a screenshot below to see the area that you need to change.