Even though you have deleted the pictures from the iCloud photo library, they are not erased from your iPhone. They are transferred to another folder on your iPhone, called Recently Deleted. This causes the "iPhone photo storage full but no photos" issue.
Check the Recently Deleted Folder
This means that deleted data still exists on your phone—and is synced to iCloud—for some time, despite you having deleted it. People commonly forget to clear this album out since the folder is buried far down in the Photos app.
If you have turned on iCloud backup and the iCloud storage is full, you will see iPhone storage full message on your phone, even there is nothing on your local iPhone or you have deleted some large documents just now.
If your iCloud Photo Library is turned on, your photos will keep appearing on your iPhone even after you delete them. This is because the device is syncing with iCloud where the photos you deleted on your iPhone will still be available. This will lead to the “iPhone photo storage full but no photos” problem.
Empty Android's cached files
If you've deleted all the files you don't need and you're still receiving the “insufficient storage available” error message, you need to clear out Android's cache.
Lots of Programs, Some Probably Unused. If you have a lot of programs installed on your computer, it can take up a significant amount of disk space. That is especially true for large programs that require a lot of storage, such as video games.
A factory reset followed by restoring your backup files is the surefire way to lower your system data. To do so, head over to Settings > General > Transfer or Reset iPhone > Erase All Content and Settings.
For example it's possible that a crash or bug or something of a technical nature might erroneously show Photos as taking up device storage when they are not. Simply rebooting the iPhone (or iPad) may resolve those type of issues and is certainly worth a try too. Have you ever encountered this before?
You can use Google Photos to save space on your device when you delete photos that are safely backed up. Before you use this feature, you must ensure that you've already backed up your photos properly.
If you use iCloud Photos, and delete photos and videos from one device, the photos and videos will be deleted on your other devices. If you add photos to your iPhone or iPad by connecting your device to your computer, you can't delete them directly from your device in the Photos app.
You cannot buy more storage space as the phone will always have the amount of storage space it came with. the only way to gain space is to delete photos, messages, apps, etc.. Be sure to save important photos and data to your comuter or an external drive.
Sometimes the "Android storage space running out but it's not" issue is caused by the overwhelming amount of data stored on your phone's internal memory. If you have many apps on your Android device and use them simultaneously, cache memory on your phone can be blocked, which leads to Android insufficient storage.
Clearing your cache removes stored data that helps websites and apps open faster, while offloading temporarily uninstalls an app without deleting any of the documents and data associated with that app. Both methods can help speed up iPhones that are slowed down by low storage.
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, check the storage recommendations or offload some less-used content like videos and apps.
On an Android Phone, Go to Settings > Storage
If you drill down into the category, you can delete individual files or data. For example, under “Audio,” long-press on one or more files and tap Delete. Or under “Apps,” tap the app's name and then Uninstall to remove it from your phone.
Ghost touch is when your iPhone screen moves or starts tapping buttons on its own. The screen seems to react to nonexistent touches, which means apps open and start doing stuff without you actually touching anything.
Remove videos, books, and music stored on your phone
Sometimes what's taking up the most amount of storage are the data and documents stored within an app on your phone. You can find out if that's the case by once again heading to Settings > General > iPhone Storage and then clicking on an app.
iCloud Photos uses your iCloud storage to keep all of your photos and videos up to date across your devices. You can make more space in iCloud when you delete photos and videos that you no longer need from the Photos app on any of your devices.
If you remove copies of photos and videos on your phone, they're now deleted but, you still can: See your photos and videos, including the ones you just removed, in the Google Photos app and photos.google.com. Edit, share, delete, and manage anything in your Google Photos library.