Hello Andrei,
The difference is that in the first response header the server redirects the client to the "AdministratorHome.aspx" page, while in the second case the server returns the requested page and does not redirect the client.
So, the question is: Why does the server redirect the client when it asks for a page? How does it know when the client needs to be redirected?
The answers to these questions are related to the logic of your server application's functioning. You need to find this out to understand why the server gives different answers to different virtual users.