WWW prefix requirement not working

I am running nop 3.4.

I have specified "WWW prefix requirement" is active in the configuration settings, but still the site does not force the prefix.

Store URL is set to http://www.store.com and SSL is enabled.

Any reason you can think of that this wouldn't be working?

Try restart application
For SSL make sure that SSL certificate is installed.

Done. Issue persists.

As for SSL information, I just wanted to provide as much info up front that could be helpful in resolving the issue.

Thanks for your quick reply. Any other ideas?

Double check http://docs.nopcommerce.com/display/nc/Setting+Up+Multi-stores here you did all correct.

I really think this is a bug in Nop 3.4.  In Nop 3.3, this worked for me with the same configuration.

Now after changing the setting in Nop 3.4, I get this error: "The page isn't redirecting properly. Firefox has detected that the server is redirecting the request for this address in a way that will never complete."

However, after setting the setting to "Pages should have WWW prefix" I did get the site to load again, but it forces redirection to non-WWW site.  No setting I set would work other this one, and it did not work per how the setting was stated.

@bradsulli, Restart application pool

I am having a similar issue, but only on secure:

I have Use WWW set for the site, and all sites (but not the store that uses a subdomain).

My results are:
http://sitename.com goes to https://www.sitename.com as expected
https://www.sitename.com also goes to https://wwww.sitename.com
But https://sitename.com goes to https://sitename.com, not https://www.sitename.com

Do I need to do a manual rewrite?  I would really rather not as I have two stores on the same domain.

I have tried restarting the application several times.

How did you solve the bug?
I have the same issue nop version 3.5

Any ideas?

The problem is also present in the latest release 3.80. If using https, it does not redirect a non WWW to WWW. Example: https://productsforautism.com does not redirect to https://www.productsforautism.com.

I solved it using IIS URL Rewrite module. It will add a rule to your Web.config.That's it. Take a look to https://blogs.iis.net/owscott/iis-url-rewrite-rewriting-non-www-to-www  article for details.