Goal reached after form fill is marked as anonymous

Goal reached after form fill is marked as anonymous

I have defined a goal in Marketing Automation > Web assistant.
Visits any page with a specific keyword in its URL.

The implementation is that one can reach the goal page after a form fill. I was expecting that the goal would be counted as an 'known', but the result is that is displayed under 'anonymous'.

What is the difference and how to handle this