Contacts app has huge data storage

Hi there, Ioann2846,

To get started troubleshooting the storage issue with the Contacts app, we recommend the following steps. Try each one in order, checking to see if the storage amount has changed between each:

1. Close all open apps: Close an app on your iPhone or iPod touch - Apple Support and restart your iPhone: Restart your iPhone - Apple Support. This will clear some system caches and allow the system time to reorganize and update its information.
2. Make sure you are on the latest iOS version available for your device: Update your iPhone, iPad, or iPod touch - Apple Support. This will ensure your iPhone has all available .
3. Update all your third party apps, particularly any that may access your contacts: How to manually update apps on your Apple device - Apple Support. This will ensure there are no conflicts with app software and your device.

Don't hesitate to respond back if you still have issues.

Hello loann2846,

I would advise to see real storage of your iOS device via iTunes on PC.

Use the Finder or iTunes to check the storage on your iOS device How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

1. On a Mac with macOS Catalina 10.15 or later, open the Finder. On a Mac with macOS Mojave 10.14 or earlier, or on a PC, open iTunes.
2. Connect your device to your computer.
3. Select your device in the Finder or in iTunes. You'll see a bar that shows how much storage your content uses, divided by content type. 
4. Move your mouse over the bar to see how much storage each content type is using.

Sometimes iOS needs time to re-calculate storage space and I would recommend to wait at least 48h.

Thanks for the reply!

Based on the information you provided and the steps taken so far, we suggest you Contact Apple Support for additional options to get this resolved.

All the best!