My contacts are out of order
QSince installing High Sierra, cards added to Contacts appear in random places, not in alphabetical order. I don’t use iCloud. How can I sort them again? by Brian Brown
AYour problem lies not in the Contacts app, but its Address Book database. If you were sharing contacts using iCloud, a good approach would be to turn off Contacts in iCloud’s preferences, remove entries when offline, then turn it back on and let your Mac resync.
You can achieve something similar without the help of iCloud, but must ensure that you have a good recent backup, in case it fails. Open Contacts, select All on My Mac in the sidebar (choose View > Show Groups if they aren’t shown) and choose File > Export > Contacts Archive. Make at least one safe copy of that exported file.
You then have a choice of two ways of emptying your old address book: you can select all the entries in Contacts and delete them, or quit the app and trash the folders in ~/Library/ Application Support/AddressBook, which is more radical.
With Contacts open and empty of contacts, choose File > Import to recover all your contacts from a copy of the archive you created. If anything goes wrong, quit the app and restore the whole of your AddressBook folder from your Time Machine backup, and you should be back where you started.
Before attempting any surgery on your Contacts address book, ensure it’s well backed up and save all its data to a Contacts Archive.