Solved
New GoTo Feature Lost - Presenter's Preview Window
My team is struggling with the loss of the thumbnail preview window for the presenter. Formerly, as a presenter, you could see what you were presenting on screen, application only or full desktop, in...
Are you using flexible layout (pop out mode) when trying to view the full screen? In which case, you can tell the screen you are sharing by the green outline. If you don't see it, you should click on the Cameras icon on the toolbar.
This article and video has helpful information on screensharing in the new app.
