After installing eM Client, video games like Fortnite and Grand Theft Auto have trouble launching and staying in full screen mode. After killing eM Client through task manager, the games can enter and stay in full screen mode. My desktop resolution is 3840x2160 @ 144hz. The games usually launch and run in 2560x1440 @ 144hz.
Operating System: Windows 10 Home Edition, Version 20H2 (19042.985)
Graphics Card: RTX 2080.
Graphics Card Driver Version: 466.63