That is because in JSF, the URL is not primarily a pointer to a JSF resource, it is a "handle" to the user's JSF session. It will change according to certain rules, but it's not the straightforward thing it is on most web platforms.
You can glue the URL more directly to the associated resource by using the "redirect" navigation directive, but there is a performance penalty.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.