Add new site to network / site created with ee


I used EasyEngine to create my 1st site with subdomain and caching with the following command.

ee stack install
ee site create --wpsubdom --wpfc

I had no trouble logging into the site and setting it up. I then tried to add an additional site to the network using the following command.

ee site create --wpsubdom --wpfc

The site created but I cannot log into it or register as a new user.

When I try and log in it says unknown user. I have setup the user via the network / site / user screen.

What is the correct way to add a site to and existing network created with easyengine?