I am running an EVGA RTX 2070 XC Gaming and I am running into this issue after a game ends, usually right around when the POTG is about to end, and it is switching to the medals window.
This is extremely frustrating because Overwatch is the ONLY game this issue occurs for. Gears4, Assassins Creed Origins, and many others did not have this problem.
I did the suggested Nvidia control panel fixes for both the Overwatch.exe and Overwatch Launcher but the issue just popped up again. Albeit it took a few days this time around after configuring. I am running 417.35 on a single monitor.