I found my problem - copied a slide that already had a very long length. But - I would still like to know the answer to my question.
I am inserting a 5 minute video from a file into a slide.
Is there a faster way to move the timeline end back to the length of m video without dragging it? I have several short videos to insert into slides and it will take me extra time to adjust each slide the way I am doing it now.