Limitations when Using Videos in Slideshows in Photos 5 on Catalina

Slideshows in Photos 5 are more limited than in previous versions of Photos.

When we include videos into a slideshow, they will play only for a second or so, and may be badly pixelated. It helps to use one of the themes, that are showing only one item per slide, without any animations. If you want to use videos in a slideshow, use the Classic Theme or Magazine.

The timing options for the slides are also currently broken. It is better to remove all background music.

Animated gifs or Live Photos will only be included as still frames in the slideshow.