“IOS” is eating my memory quota

Hello 暟宸,

In the screenshot you posted, we noticed that "iOS" is taking up 8.89 GB of storage on your device. Generally, when you see this it means an update has been downloaded to your device, but not yet installed. This would mean the current iOS version it's running and the newer uninstalled version are both taking up space on your device.

If this is the case, we'd recommend installing the update, as this could help with freeing up some space , along with addressing any unexpected behavior you're seeing with the internal storage on your device. Update your iPhone or iPad will walk you through this.

1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see more than one software update option available, choose the one that you want to install.
5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

If you continue to see issues, the "Content categories" section of How to check the storage on your iPhone and iPad provides additional insight on the different categories you're seeing, and what they include. This may help you determine what to delete from the device that would have the biggest impact.

"Content categories 

The used content on your device is divided in these categories:

• Apps: Installed apps and their content, and content stored in "On My iPhone/iPad/iPod touch" directory in the Files app, and Safari downloads 
• Photos: Photos and videos stored in the Photos app
• Media: Music, videos, podcasts, ringtones, artwork, and Voice Memos
• Mail: Emails and their attachments
• Apple Books: Books and PDFs in the Books app
• Messages: Messages and their attachments
• iCloud Drive: iCloud Drive content that has been downloaded locally to your device. This content can't be automatically deleted.
• Other: Non-removable mobile assets, like Siri voices, fonts, dictionaries, non-removable logs and caches, Spotlight index, and system data, such as Keychain and CloudKit Database. Cached files can't be deleted by the system.
• System: Space taken by the operating system. This can vary based on your device and model."

Regards.