Why might the left nozzle fail to pick up material for 3 consecutive times?

What should be checked to ensure the feeder's discharging position is correct?

What could be causing the material belt to stick, and how might it be resolved?
The solution for M113 error involves checking whether the Feeder discharging position is correct and if the material belt is stuck. If the feeder is not discharging material, adjust the discharge position. If the belt is stuck