Other Users can’t view multisite

I have set up a multi-site and on my administrator account, have no issues navigating between my two websites.

I created a new user, with administrator privileges, and when the new user is logged in, they can only view the main site. When the new user hovers over “My Sites” it only lists the main site, and not the other one. And they don’t see “Network Admin”

Is there something I need to do to set the new user up to be able to edit both sites? Or will the original administrator be the only one who can?