Zoom webinar speaker view for attendees

Hi,

I just had a webinar session.  I had 4-5 panellists in the session so I expect our attendees to see as if the "Active Speaker View" in the zoom meeting such that The Active Speaker in the biggest window with smaller windows of other speakers on the top.  So I set the Attendees View as Speaker View.

But when I cross checked my attendees login from my iPad and Mac, the Speaker View only show the single speaker in the whole screen.

Did I set it up wrongly?  I could not find any clue.

Edit: Quoting Managing attendees and panelists in a webinar - Attendee view controls 

• Speaker: Speaker view switches between the active speakers in the webinar, with other video panelists above the active speaker when not speaking.