Sometimes Contact names can go missing on iPhone, showing only numbers and not names. You will find below a number of methods to fix the problem of Contact Names missing on iPhone Message Notifications.
1. Turn iMessages OFF/ON
The problem of Contact Names missing on iPhone could be due to minor software glitches in the Messages app. This can be often fixed by restarting iMessages.
1.1. Open Settings > Messages > turn OFF iMessage.
1.2. Restart your iPhone.
1.3. Open Settings > Messages > turn ON iMessage.
2. Edit Any Contact
Open the Contacts App on your iPhone and make a minor edit to any of the Contacts. This act refreshes the Contacts database and is known to fix the problem of Contact Names Missing on iPhone.
2.1. Open the Contacts App on your iPhone > tap on any Contact Name.
2.2. On the Contacts info screen, tap on the Edit option and make any small change.
You can make any small change like Adding something in notes section and tap on Done.
This will Refresh the Contacts database on your iPhone and can often fix the problem of Missing Contact names on iPhone in Message notifications.
3. Toggle Contacts OFF/ON in Default Email Account
The problem of Contacts Missing in Message Notification on iPhone could be due to an issue in syncing of Contacts between your Email Account and iPhone.
3.1. Open Settings > tap on Accounts & Passwords.
3.2. On the Accounts & Password screen, tap on your default Email Account (Gmail, Hotmail, iCloud etc)
3.3. On the Account info screen, move the slider next to Contacts to OFF position.
3.4. Restart your iPhone.
3.5. Open Settings > Accounts & Passwords > tap default Email Account.
3.6. On the next screen, move the slider next to Contacts to ON position.
4. Toggle Contacts OFF/ON in iCloud
In case your iPhone is set to sync Contacts from iCloud, toggling iCloud Contacts OFF/ON can fix the problem of Contact Names missing on iPhone.
4.1. Open Settings > tap on your Apple ID.
4.2. On the Apple ID screen, tap on iCloud.
4.3. On the iCloud screen, move the slider next to Contacts to OFF position.
4.4. Restart your iPhone.
4.5. Open Settings > tap on Apple ID > iCloud > Enable iCloud Contacts.