When enabling vsync, the fps is higher away from 60

When it active vsync, the fps is highist AWAY from 60 or 30!!!

Reproduce:
1.Press Esc
2.Click the Options, Video Settings
3.Toggle the vsync to ON
4.Click "Done"
5.Click "Back to Game"
6.Press F3 and check the fps
7.We was TOO HIGH fps on vsync