This bug has been driving me mad for over a year now and it's never been fixed even though I have reported it before.
SetVSync does not work correctly on MacOS ( currently Big Sur ) - Same hardware using Windows 10 and it works correctly.
With the below code toggling the SetVSync setting between 0 and 1 shows the following on a 144hz monitor :
Windows 144fps or 1000's of FPS ( correct )
MacOS 60pfs or 1000's of FPS ( incorrect ) - On different version of AppGameKit the refresh rate is variable from 60 to 110 which too is incorrect on a 144hz monitor.
SetWindowTitle( "vSync Issue" )
SetWindowSize( 1024, 768, 0 )
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
UseNewDefaultFonts( 1 )
SetVSync( 1 )
Print( ScreenFPS() )
NOTE : I do not use SetSyncRate() to force an FPS.