Navigation button and page link not working

Hi, 

I'm working on a site with a members area. In the site nav I've added the button feature, and renamed it 'LOGIN' and the page linked to that button is the homepage of my members area.

This issue I'm having is that I have designed a Members Area homepage, which I want the user to be directed to once they hit login, however, when I click the login button (after logging out of SS and using the site as if I were a customer) the button directs me to a page that is not only not in my list of created pages, and therefore uneditable/deleteable, it also has a button that asks me to join, which then takes me to a payment details page. 

In other words, the page link I have assigned to the button doesn't seem to be accessible...

Site link: https://strongly.health/