You may need to determine which attributes should be getting pulled in from AD or other endpoints during an Explore/Correlate so you can setup Correlation Rules to pull in any attributes that are not set by default.
You can view the default Explore/Correlate values in the Provisioning Manager.
1. Go to: System / Domain Configuration / Explore and Correlate / Correlate Attribute
2. Click the checkbox entitled 'Restore default.'
It will display the default attributes.
3. Uncheck 'Restore default' when done.