I backed up to Icloud, but not all of my contacts were saved to icloud. How do I fix this?

Hi egrisotti,

​Thank you for using the Apple Support Communities. It's certainly important to make sure your content is backed up, and we'd like to help out.

To clarify, are you syncing your contacts to iCloud by turning on Settings > [name] > iCloud > Contacts? If so, your contacts will sync between your devices rather than backing up. If that's the case, check this out If your iCloud Contacts, Calendars, or Reminders won’t sync.

On the other hand, if you restored a backup and found some of your contacts weren't there after, were you using any third-party accounts to hold contacts? If so, you might need to re-add those accounts and turn Contacts on for those: Use other contact accounts on iPhone

Let us know if this helps. Kind regards.