Sharing the screen with MS office powerpoint presentation in F5 regime

Sharing the screen with a ppt presentation is working only in a “working view” regime (the list of slides in the left column visible). When the speaker turns on the presenation view regime (F5) it is only visible for him but the other participants can see only the same working view with the list of slides on the left. We tried in Firefox and Chrome with the same result, with MS office 2019 (and Windows 10). How to fix it? Thank you.