Automatic Water Distributor Art. No. 1198/1197 isn’t switching to the next step. What could be the possible reasons for this?

The pauses between the programmes/outputs are too short. The inlet pressure is too low. The output volume is too large. This means that the orange piston is either not fully extended during operation or it has not yet fully reached down into the next outlet during the pause. Automatic Water Distributor (1198/1197)