Seeing participants' names while sharing a powerpoint or screen (Mac)

When I share a powerpoint or whiteboard, etc. I keep the gallery view as well. However, the participants' names vanish and won't reappear even if I hover. When I stop sharing the names reappear. I need to be able to share my screen/ppt and also be able to use participants' names to build an interactive workshop, with people I don't know. How can I keep the names available? Apparently they don't disappear on a PC.  Thank you