The reason for this is that the successRedirect is hardcoded to users_Profile.php and the faileRedirect is hardcoded to loop back to the login page with a failed url variable. You would want to append any of the url variables to that dynamically if you wanted to retain them. Make sure you don't append the failed=1 to the successRedirect if there is one.
On your users_Login.php page, you would want to make these modifications on these lines:
"successRedirect" => "users_Profile.php",
"failRedirect" => "users_LogIn.php?failed=1",
The successRedirect is in two places.