1. Ensure that the duplicate slide has the same transitions, effects, and animations as the original slide.

Check the Design ribbon for the respective options.

2. Check to make sure all the images, clipart, and videos are properly linked to the slides.

Disable any content auto-updating settings.

3. Reset the timing of the animations on the duplicate slide.

Access the Animations ribbon and adjust the animations as neccessary.

4. Check if the duplication process caused any new slide elements or objects.

Duplicating a slide may cause objects to overlap or appear in wrong positions.

5. Reset the layout of the slide to its default.

Ensure that the slide elements have been properly formatted.