UHD 620 sets the frame rate (60 FPS) for the secondary display (external monitor has 144 Hz) in line with the primary display refresh rate (laptop in-built display has 60 Hz).
When an external monitor is not set as the primary display, test results will indicate a 60 Hz refresh rate and 60 FPS. Although not visible in captures, the visual quality of moving objects is significant.
UHD 620 sets the frame rate for the secondary display in line with the primary display refresh rate (for example, if a laptop built-in display has 60 Hz it may set an external monitor with 144 Hz refresh rate to 60 Hz).
Furthermore, due to web browser VSYNC synchronization, external monitors are limited to the refresh rate of the primary display.
With our driver and Intel® Graphics Command Center the Vsync control is passed on to the OS. By default, the OS will make Vsync synchronize each application with the display it starts on first (at 1st launch they often display on the primary display).
The applications should be set so they start on the secondary (higher spec) monitor, which should make the expected frame rate goal to match the display's refresh rate as per Vsync. Often times moving the application to the 2nd display and closing it while on this one will cause it to begin defaulting to the desired display (on 2nd execution the app should start on the monitor it was previously closed.)
An alternative would be to test with the Intel Graphics Control Panel, which instead of letting Vsync be controlled by the OS, allows the user to define Vsync behavior.
To do this, go to 3D > Global Settings > Turn on 'Application Optimal Mode'. And also under 3D -> Applications settings -> select 'User driver settings' so the driver will synchronize the display of images with the screen refresh rate.