The command to JOIN two overlapping anchor points as a SMOOTH join is not working (at least, on Mac).
"The join option only results in a corner join regardless of whether you select anchor points to join or the entire path. However, for overlapping anchor points, if you want the option to select a smooth or corner join, then use Ctrl+Shift+Alt+J (Windows) or Cmd+Shift+Option+J (Mac OS)."