Why does my presentation jump to the next slide automatically?

Suddenly in my presentation, my slides jump automatically to the next slide. I don't have a trigger telling them to do so (though I used to), and I do have a trigger telling it to jump to the next slide when the user clicks the Next button.

Nothing I've done seems to be able to stop it (including saving, going completely out of the presentation and back in again)

Any ideas?

Thanks so much!