I’ve lost hundreds of contacts since the latest update, some very important numbers. I’ve had the same account for too many years to remember. Of course my back ups are recent so no longer have this information either.
iPhone 14 Pro Max
Contacts are not contained in backups, they sync to your email provider(s) servers. If you have changed any email settings, or deleted or logged out of an email account all of its contacts will go with it.
If these contacts were specifically associated with your iCloud/Apple ID account see→iCloud: Restore contacts, calendars, and more in iCloud Settings
Contacts are not included in iPhone backups.
if you restored using the iCloud link instructions and you did not get them back that means they were no iCloud saved contacts, they were backed up by a different email service.
I did a restore from last month, they are still gone.
Missing Contacts after 18.1.1 Update
