If you are an iphone user and you are facing the problem of iphone contacts disappearing. Then first, you need to know that, you are not only person who suffering with this issue. this is a common issue which is facing by many iphone users, these days But no need to worry because we are here with the solution of this issue you can fix this issue by following some easy steps.
Sign out iCloud and sign in again
change the contact group settings.
Turn off and then on iCloud for contact
Select your iphone as default
Restore iPhone on Finder/ iTunes