I've been experiencing this problem for a while - when presenting using Microsoft PowerPoint for Mac 2016 (version 15) on an external monitor (or LCD projector), PowerPoint used to both the presentation slide show and the Presenter View on my notebook display, instead of Presenter View on the notebook and the full-screen slide show on the external monitor. Recently, I found the solution!

In short, to fix the wrong monitor issue, simply make sure PowerPoint is not assigned to any Desktop.

Assigning an app to a Desktop (space) makes it open in that Desktop every time it is started up.

The Workaround

Before I discovered the solution, both the Presenter View and slide show were on my notebook display, with the latter partially obscuring the former!

PowerPoint's Presenter View and Slide Show on Same Display

So I had to:

  • Do the three-finger swipe to get to the Mission Control layout.
  • Click on the Presenter View to focus on it - often this took a few tries, since the presenter view would grab focus again.
  • Click on the Swap Displays icon, which moved the Presenter View to the external monitor.
  • Move my mouse to the external monitor, then click Swap Displays again, to get move the Presenter View back to my notebook and the slide show to the external monitor.

PowerPoint Presenter View toolbar Swap Displays button

All this while in front of an audience. Very stressful and embarrassing!

The Solution

The solution is simply make sure that PowerPoint app is NOT Assigned To a Desktop (space). With PowerPoint running:

  • Right-click PowerPoint in the Dock.
  • Under Options > Assign To, select None.

Dock Options Assign To Desktop Menu

DO NOT select This Desktop or any numbered Desktop (which makes PowerPoint "stick" to the particular space/desktop).

DO NOT select All Desktops (which makes PowerPoint appear on all desktops).

The Details

To get Presenter View going on a Mac after connecting your external monitor:

  • From the macOS Menu Bar right-click on the Displays icon and select Separate Monitor

  • If the Displays icon is missing, head over to System Preferences > Displays and make sure Show mirroring options in the menu bar when available is checked.

  • Also here, you can make sure that, under the Arrangement tab, Mirrored Displays is not checked.

System Preferences Displays Arrangement Mirrored Display

Now the external monitor will show a separate desktop, different from what you are seeing on your notebook.

Next, to enable Presenter View in PowerPoint:

  • From the PowerPoint Command Bar or menu, Slide Show > Set Up Slide Show.
  • Under Show Type, select Presented by a speaker (full screen) and under Monitors, leave Slide Show Monitor as Automatic or explicitly select the external Monitor 2.

PowerPoint Set Up Slide Slow on Monitor 2

Assuming PowerPoint is NOT Assign(ed) To any Desktop, then you'll get:

PowerPoint Slide Slow on External Monitor

Hope this helped you too!