Thanks! Going to sound mixer options lets me mute the sound in Edge but not from Teams installed as a progressive web app (PWA). So, I have to use Teams in a browser for the second instance.
In case any other teachers are looking for a way to see their students while presenting their screen. Here is the list of steps that are working for me. This is ridiculously complicated in my opinion and I can't wait until Microsoft builds this capability into Teams. Seriously, if you miss a single step, you'll end up with a mess of echoes or infinite screens showing.
I use Chrome as my default browser. So, I am forcing the second instance of Teams to open in my MS Edge browser so that it doesn't get lost among the tabs in my Chrome browser.
Part 1: Create Edge shortcut on monitor #2
- Right-click on the desktop
- Click on new
- Click on Shortcut
- For the location type in microsoft-edge:http://teams.microsoft.com
- Give the shortcut a name like Teams in Edge
Part 2: Join the Teams meeting from the Edge browser shortcut on your 2nd monitor
- Click on the desktop shortcut you just created on monitor #2 to open Teams in the Edge browser
- In the Start menu search bar type Sound Mixer Options
- Select Sound Mixer Options from the best match list
- Find Microsoft Edge on the list and set its volume to 0
- Join the meeting from the Edge Browser on Monitor #2
Part 3: Join the Teams meeting from the desktop app on your 1st monitor
- Join the meeting from the Teams desktop app on monitor #1
- Turn off your audio in the Teams desktop app
- Turn off your video in the Teams desktop app
Part 4: Share your content (screen or individual apps) from Monitor #1
- Share any content in the Teams desktop app on monitor 1. The desktop app is the most full-featured for sharing content.
- Because your mic and camera are controlled by the Teams meeting in the Edge browser on monitor #2, it should be easier to find your meeting controls to mute/unmute yourself. You will also be able to see participants' video in a strip along the bottom and the chat window if you set it to show.