TeamViewer Invite Contacts in a Meeting

Dear All,

I would like to start an instant meeting for screen sharing and talking purposes. I use the following method: click on Meeting, then Presentation, then I would like to add my partner who is actually there in my Contacts. But I cannot add him. What should I do at point 5. in the attached screenshot? Double click on my partner doesn't work (it simply doesn't do anything), Enter also doesn't work. Did I encounter a bug or do I miss something here?

The other approach works fine (first click on my partner and then click on Presentation on his detail page).

Thanks!