SSRS 2016 with SSL Prompting for Credentials

I have a test server set up with SQL Server 2016 and SSRS 2016.  I have the SSRS instance in native mode set up with SSL.    Whenever I go to the Web Portal URL or the Report Server URL, I get prompted for my credentials.  I have verified that the rsReportServer.config file has only <RSWindowsNTLM/> for the AuthenticationType.  The SSRS instance is in the domain and the non-SSL URLS do not prompt for credentials.  I have tried Kerberos by having the SPNS created for the SSL URLs and adding  <RSWindowsNegotiate/>. This doesn't work either.  I don't see any errors in the log files either.

I have scoured posts about SSL and SSRS and the settings for the rsReportServer.config file.  I am sure I am just missing something.  Can someone give advice?  

Thanks in advance.

jbud55