Previously, wplms was purely based on wordpress. In this new version we are conversting wordpress based wplms into Progressive Web Application(PWA) using react js
So One login is wordpress login and the other login is fetching the login details and loading the components according to that, because it fetch the user details and teh components and everything will be loaded according to that(in profile section)
That's why we need two login
But if you will enable this setting from wp-admin > vibebp - settings ->
http://prntscr.com/tpoa22
The reactjs login will be automatically synced with wordpress login so you need not to login two times