We just went live on Docebo about a month ago and are still trying to figure out best practices for playlists. Learners often see the "No More Users to Invite" message after clicking “Invite to Watch” even when they haven't shared with anyone yet (these are private playlists but they are published). So there should be plenty of people to invite. In my testing, it looks like we can sometimes choose individuals to invite when attempting from the playlist card on the My Channel view but not when we attempt to invite from the playlist itself. 

Also, does anyone know how Docebo chooses the “suggested users” on the Invite to Watch page? Sometimes they make sense (people we interact with often) and other times they are seemingly random (test accounts, etc.)