Dell Mobile Connect is open in another window

Dell Mobile Connect (DMC) was working and then without warning it was not. It presented the following message with a yellow triangle, "Dell Mobile Connect is open in another window—Use Dell Mobile Connect in this window." It provided one action option, "USE IN THIS WINDOW," but when selected, the DMC dashboard flickers and the problem persists. I verified that there is only one window open on the screen, but the message persists. I am a novice (and elderly) and don't know what actions or steps to take to solve this issue. Please help. 

I provide the following support information to assist with troubleshooting:

PC: DELL XPS 8930, i7-9700 CPU @3GHz (8 Cores), 64-bits, Windows 10 Pro, 16GB Memory

DMC: Dell Mobile Connect-NEW, Screenovate Technologies, Version:u:..10192/c:4.0.6072.0, Release Date 1/13/2021, 68.28MB

[The NEW DMC and NEW DMC Companion are installed on my PC and Samsung Note 10 respectively.]

ScreenShot