Group Owners Missing Invite Member Section in Group Members Page

Running GitLab CE, Omnibus installer, version 12.9.1-ee (0ebcf602332). Group owners are unable to add users to their groups. The “Members” page is completely lacking the “Invite member” section. Compare this to the page I see, when logged in as an Administrator, which DOES show the Invite Member section. Is this an Enterprise Edition, or paid option, only?

I have a similar issue, does anyone have an idea?