So, we have the following issue:
1. Agent opens a ticket, and the User profile tab is opened.
2. Agent opens a new tab with search in Zendesk and searches for something.
3. From search agent visits user profile on address https://<domain>.zendesk.com/agent/users/<userid>/requested_tickets
4. Agent returns to the ticket from the first point, and the User profile tab is now hidden, and agent has to click again to open it. 

This is an annoying little bug, and I hope it can be fixed. Screen with User profile tab opened: