Hi lutricia113,
Thank you for posting in Apple Support Communities!
If your device is low on storage it automatically frees up space. You'll want to free up some space on your device in order to have your content downloaded back to your device.
Check out: How to check the storage on your iPhone and iPad - Apple Support
Use your device to check its storage
1. Go to Settings > General > [Device] Storage. You might see a list of recommendations for optimizing your device's storage, followed by a list of installed apps and the amount of storage each one uses.
2. Tap an app's name for more information about its storage. Cached data and temporary data might not be counted as usage.
In the detailed view you can:
-Offload the app, which frees up storage used by the app, but keeps its documents and data.
-Delete the app, which removes the app and its related data.
-Depending on the app, you might be able to delete some of its documents and data.
If your device is almost full and can't free up space, you might get a Storage Almost Full alert. If you see this alert, you should check the storage recommendations or you need to offload some less-used content like videos and apps.
You can also find additional information on missing photos/videos here: If you're missing photos or videos in the Photos app - Apple Support
Hope that helps!