Zoom Meeting flashes black around 6x when sharing screen and performance issues afterwards.

Since about early September,  when I start up a zoom meeting, and share a window, the screen will flash black around 6 times before it finally comes back to the screen.    There is red text that states Please move this window away from the shared application, even though there is nothing else being shared, on top of the shared screen.    In addition the text gets bigger, and my machine performance is degraded until I reboot.

I have the latest zoom software, Windows 10, Dell 5550 machine.