Audi 80 Type 89 : Coupling pedal goes to the ground

Hello, have problems with my clutch: Either the pedal does not go back completely or sometimes the clutch pedal, as operated by ghost hand, goes back to the bottom sheet and remains there. You have to pull it up again and then it goes back until it is repeated at some point. Did the clutch ventilate, without success. Can it be that the encoder cylinder causes this phenomenon? Or can the clutch hose cause this going down by springing up when the pedal is operated ??