I have made changes to a PowerPoint slideshow that is already in my schedule and add it into the schedule again, but the thumbnails that appear are from the original slideshow. 

Follow the steps below to work around this issue. 

  1. Make changes to the PowerPoint slideshow. 
  2. Make sure the slideshow in the schedule is not live, or being presented. 
  3. Remove it from the schedule and save the schedule. 
  4. Drag the updated PowerPoint into the schedule and save the schedule.