When you are asked to push the clock, please try pressing the analog stick in different directions as you get closer to the door. You will need to angle the stick towards the direction of the door as you move closer to it.
If you press left and then stop while pushing, please press the stick in a diagonal northwest direction, then upwards when you are near the door. This should prompt Michonne to continue pushing the clock.
If you are not sure which direction to move, try moving the stick in circular motions until Michonne moves.