Does anyone out there know why “adding members” only brings up a search function, rather than an actual invitation function?
There are two places to add members: to a team and to a space. It sounds like you’re seeing the dialogue to add members to a space, which will only show you people on your team already. Once you add them to the team, then you can add them to any spaces you’d like them to be in.
To add a member to your team, go to Settings, click on your team name, then on Team Directory. Clicking the + button then gives you dialogue to add team members.