I have a new HP Windows 10 computer and and ACER G276HL monitor.
The monitor is set to be the primary screen and works well.
The issue I have is every time after the computer goes to sleep mode, all screens are moved onto the monitor, including the ones which were on the PC display when the computer went into sleep mode.
Additionally, some screens (Excel seems to be the worst) open up wider than the monitor and I have to double click on the header to get it onto one screen, then I can maximize before using.
I have updated the monitor drivers - it uses the "Generic PNP Monitor" and ACER does not provide a Windows 10 driver for this monitor.