OSD (On-screen display) does not respond to touch or anything; just sits there

New Dell 7720 27" AIO

When I increase the brightness of the screen above 74%, I get an OSD message (in a gray box in the bottom right of the screen) with a yes or no response, and below the box a gray circle with up down left and right arrows and an OK in the middle.

None of the OSD elements responds to my touch.  Note though that i can touch the screen and interact with anything on the regular screen: applications, menus, etc.  It is just the OSD pop ups that do not respond to touch (or anything else)

I'm stuck!  Help!

Thanks.