All sliders are automatically cached the first time when they're viewed by a visitor, so next time when someone visits the page, the slider will be served from the cache. This mechanism saves processing time and is especially useful when loading content from posts or external services.
When a slider is updated in the admin area, the cached version of the slider will be deleted. Also, you can deleted all cached sliders from within the Slider Pro -> Plugin Settings page, by clicking on the Clear all cache now button.
If you want to not cache a slider, you can set the allow_cache attribute to false , in the shortcode:
[sliderpro id="3" allow_cache="false"]