Question: Did you recently remove an email account from your iPhone? If YES, then those contacts may have been associated with that email account. You can try adding it back again and see whether those contacts get added again.
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If you accidentally deleted your calendars, bookmarks, or contacts from iCloud
You can go to 👉 www.icloud.com and restore your missing calendars, bookmarks, or contacts from an earlier version.
When you restore from an earlier version, the version that you select will replace the existing calendars, bookmarks, or contacts on all your devices. Before you restore an earlier version, iCloud saves your current calendars, bookmarks, or contacts, so that if you want to reverse the restore, you can. Just repeat the steps to restore, and select the latest date to restore from.
If you recently made changes, you might lose some data.
You might want to create a backup before restoring.
Restore your contacts or bookmarks from an earlier version
1. From your iPad or computer, sign in to iCloud.com.
2. Click your name at the top of the iCloud.com window, then click Account Settings.
3. Scroll down to the bottom of the page. Under Advanced, click Restore Contacts or Restore Bookmarks.
4. Click Restore next to the date before you deleted the content.
5. Click Restore again to confirm. After the restore completes, you'll get a notification on iCloud.com and an email to the address on file with your Apple ID.
Axel F.