Gallery view while screen sharing

[Des7]

I work with dual screens giving presentations. I’m sharing a PowerPoint. One screen (that I’m sharing) has the slide I’m speaking to while  the other has the “speaker notes” page. I have the gallery view up but every time I move the cursor (like to advance to the next slide) I lose my gallery view. I have to keep going back to the tool bar and clicking on the zoom icon and then pull that gallery window back up. What am I doing wrong??