To reproduce:
1) Open the attached project
2) Load 'tutorial-done' scene
3) Run project and press 'space' button, you will notice that it causes game object to jump, but without reaching ground, this is undesired.
4) Now open 'BotControlScript.cs', comment 48th line to remove lag and then save it
5) Now run project again and you will notice that game object now reaches ground, this is what user wants.