A really quick post on an issue I had the other week.
The environment was https and all appropriate certs were in place. The production environment was working perfectly but in dev, when we used the FQDN to reach the report server we kept getting prompted for credentials. After double checking everything was set up exactly as I’d set it up for prod I found the credentials kept appearing. I tested the scenario without https and there were no prompts.
I added the site to the local intranet sites in IE and the prompting went away. A GPO might be called for if you experience this in an enterprise environment.