Not able to perform updates on resource/user

Summary:

I am trying to update fields on resource via import and getting this error - An error occurred during the data import. Details: This error occurred while importing data: The email address tuc1@test.com already exists for another resource. You must enter a different email address. (HZ-120830).

When deleting contact points(email and phone) for contacts, even the resource email and phone got deleted. Because of this update operation on resource is failing and even from resource directory not able to do any updates on resource. And Email Address field on resource still shows the right email in UI - 'tuc1@test.com' but not able to do any updates on the resource. How to solve this