is this a bug?

Hi @Zeal Caduyac,  

The Contact object in this org has Street Address marked as a required field (either standard field requirement, validation rule, or custom configuration), but Salesforce could not find a matching column from your CSV file.

You can fix this in below ways:

1. Click OK.
2. Click Show errors or locate the row for Contact: Street Address in the field mapping screen.
3. Click Change next to that field.
4. Map it to the CSV column that contains the contact's street address.
5. If your CSV doesn't have a street address column, then: 
   • Add a Street Address column to the CSV and populate it, or
   • Review whether the field is being made required by: 
     • validation rule
     • page layout setting
     • custom field configuration
     • before-save flow or trigger
6. If Street Address is not required, consider updating the field configuration or related validation rules to make it optional, then retry the import.