When you add a GIF to Google Slides, it will play even if you are not on the slide that it lives on. If you refresh the page, you will see that the GIF starts to play in the thumbnail. Therefore, when you reach the slide in presentation, the animation has already played. Even if you have a "Appear on click" command, the animation is already at the last frame and does nothing.
Is there a way that a GIF can stop at the first frame and not play until you click on the page that it is on?