Problem:

Contacts' names are not displayed in WhatsApp, while their phone numbers are displayed.

Cause:

The permission to access Contacts has not been enabled for WhatsApp. As a result, WhatsApp cannot obtain contact information.

Solution:

1. Allow WhatsApp to access Contacts: Go to Settings > Apps > Apps, touch WhatsApp, and enable the Contacts permission.
2. Click Force stop, return to the home screen, and restart the WhatsApp app.