Pendulum won't finish the swaying until your almost touching it.
Adding save file... If you start up the save file you'll see that the pendulum sways a couple of times and then stops. If you now move in close to it, you'll see that it suddenly starts swaying again and finally finishes levelling out. What this means is that If you don't know this, it's going to be impossible to ever get it working and show you what is 100% levelled. The pendulum should be able to finish levelling with out you having to stand up against it.