Protected Content has been a nightmare for me. I am trying

Protected Content has been a nightmare for me.

I am trying to protect a page which contains shortcode for a document manager, and it's not working. After login, I see the Account page, but then when I try to go to the Protected page, I get prompted to login again.

I did a similar thing some time back with Password Protect and SP Client Documents, but am trying to be more sophisticated this time, with multiple users, and it's just not working out for me.

For starters, should I point users to the protected page directly, or have them login on another page, does that matter at all, it should work, regardless, right?

On a related note, I am looking for a way to ensure that there's no caching of any kind during development on WP. How can that be achieved? I am still seeing markup in the browser that should have been long gone, based on what I see in the Admin.

Thanks!