Reporting Services - Host header and Windows Authentication SQL 2016 - Enterprise Edition
Windows 2016
Reporting Services runs on domain account (SPN registered for new host header)

Problem:
When adding a host header in Reporting Services Configuration tool, like reports.server.net,  users need to login to the reporting services.
When I remove the host header and try to connect to hostname/reports I do not get prompted for user/password.

Fact:
 - When i use the default site address http://servername/Reports, before adding a new host header, the site opens up without login prompt

What I've done:


Created a Host record in DNS for the new address, pointing at reporting services server
Registered a SPN for the new host record to the service account for reporting service
Added the new host header to reporting services for web service url and web portal url
Played around authentication types in the reportserver.config file according to (https://docs.microsoft.com/en-us/sql/reporting-services/security/configure-windows-authentication-on-the-report-server?view=sql-server-ver15&amp;viewFallbackFrom=sql-server-ver13)
Enabled delegation for the reporting services service account "just in case"


I can't seem to add a host header without beening forced to login, despite above.

Anyone been here?
Solved issue by adding new host header address to local intranet site in the browser.