Connecting visitors in different browsers

We are tracking a forgot password workflow action using adobe site catalyst. The flow happens something like below

1. User requests for forgot password
2. He provides the email address and clicks on create new password
3. New password generation like is send to his email address
4. User clicks on this link and generates a new password

First 3 actions occurs in the same browser. The 4th activity can occur in the same browser or a different browser. Because of this, site catalyst considers that user as a different one (different visitor ID) and considers that as a totally different visit. Ideally the number of users who completes activity 4 should be less than that completes 1,2,3. But for us, we are seeing more users who completes activity 4 which could be because of this different visitor issue.

Can someone please suggest a better approach to solve this?