I don’t think adding a site doesn’t work the same way as Last Pass. The tutorial video indicated that instead of logging in and expect Bitwarden to log in, the proper method appears to be to click on Bitwarden and click on add site, which will populate it with the necessary URL and then you would enter the user name and password. This is definitely less intuitive than using Last Pass, but I don’t regularly add sites, so I decided that this is not an issue to manually add the site.
In Last Pass, I notice that the feature works a lot of time and sometimes it doesn’t work. It seems to be affected by updates, which Logmein will update again to fix. As a result, I usually end up adding the entry manually any way.