Advanced pause feature - strange behaviour (no replies)

Hi guys,

'm kind of deperate getting the advanced pause feature issued by an M600 to work the way I expect it to.
I'm using Marlin 2.0 on an Ender 3 and here is what my configuration of the feature looks like:

#define ADVANCED_PAUSE_FEATURE
#if ENABLED(ADVANCED_PAUSE_FEATURE)
  #define PAUSE_PARK_RETRACT_FEEDRATE         60  // (mm/s) Initial retract feedrate.
  #define PAUSE_PARK_RETRACT_LENGTH            3  // (mm) Initial retract.
                                                  // This short retract is done immediately, before parking the nozzle.
  #define FILAMENT_CHANGE_UNLOAD_FEEDRATE     10  // (mm/s) Unload filament feedrate. This can be pretty fast.
  #define FILAMENT_CHANGE_UNLOAD_ACCEL        25  // (mm/s^2) Lower acceleration may allow a faster feedrate.
  #define FILAMENT_CHANGE_UNLOAD_LENGTH      100  // (mm) The length of filament for a complete unload.
                                                  //   For Bowden, the full length of the tube and nozzle.
                                                  //   For direct drive, the full length of the nozzle.
                                                  //   Set to 0 for manual unloading.
  #define FILAMENT_CHANGE_SLOW_LOAD_FEEDRATE   6  // (mm/s) Slow move when starting load.
  #define FILAMENT_CHANGE_SLOW_LOAD_LENGTH    25  // (mm) Slow length, to allow time to insert material.
                                                  // 0 to disable start loading and skip to fast load only
  #define FILAMENT_CHANGE_FAST_LOAD_FEEDRATE   6  // (mm/s) Load filament feedrate. This can be pretty fast.
  #define FILAMENT_CHANGE_FAST_LOAD_ACCEL     25  // (mm/s^2) Lower acceleration may allow a faster feedrate.
  #define FILAMENT_CHANGE_FAST_LOAD_LENGTH    25  // (mm) Load length of filament, from extruder gear to nozzle.
                                                  //   For Bowden, the full length of the tube and nozzle.
                                                  //   For direct drive, the full length of the nozzle.
  #define ADVANCED_PAUSE_CONTINUOUS_PURGE         // Purge continuously up to the purge length until interrupted.
  #define ADVANCED_PAUSE_PURGE_FEEDRATE        3  // (mm/s) Extrude feedrate (after loading). Should be slower than load feedrate.
  #define ADVANCED_PAUSE_PURGE_LENGTH         0  // (mm) Length to extrude after loading.
                                                  //   Set to 0 for manual extrusion.
                                                  //   Filament can be extruded repeatedly from the Filament Change menu
                                                  //   until extrusion is consistent, and to purge old filament.
  #define ADVANCED_PAUSE_RESUME_PRIME          2  // (mm) Extra distance to prime nozzle after returning from park.
  //#define ADVANCED_PAUSE_FANS_PAUSE             // Turn off print-cooling fans while the machine is paused.

                                                  // Filament Unload does a Retract, Delay, and Purge first:
  #define FILAMENT_UNLOAD_PURGE_RETRACT       13  // (mm) Unload initial retract length.
  #define FILAMENT_UNLOAD_PURGE_DELAY       5000  // (ms) Delay for the filament to cool after retract.
  #define FILAMENT_UNLOAD_PURGE_LENGTH         8  // (mm) An unretract is done, then this length is purged.
  #define FILAMENT_UNLOAD_PURGE_FEEDRATE      25  // (mm/s) feedrate to purge before unload

  #define PAUSE_PARK_NOZZLE_TIMEOUT          300  // (seconds) Time limit before the nozzle is turned off for safety.
  #define FILAMENT_CHANGE_ALERT_BEEPS          0  // Number of alert beeps to play when a response is needed.
  #define PAUSE_PARK_NO_STEPPER_TIMEOUT           // Enable for XYZ steppers to stay powered on during filament change.

  //#define PARK_HEAD_ON_PAUSE                    // Park the nozzle during pause and filament change.
  //#define HOME_BEFORE_FILAMENT_CHANGE           // If needed, home before parking for filament change

  //#define FILAMENT_LOAD_UNLOAD_GCODES           // Add M701/M702 Load/Unload G-codes, plus Load/Unload in the LCD Prepare menu.
  //#define FILAMENT_UNLOAD_ALL_EXTRUDERS         // Allow M702 to unload all extruders above a minimum target temp (as set by M302)
#endif

I set ADVANCED_PAUSE_PURGE_LENGTH to zero since the instruction tells me to so in case I want to go for manual extrusion.

Whenever a print reaches the point for filament change and M600 is issued, the print stops, the printhead moves to my predefined parking position (works properly) and it unloads a bit of filament. The rest of the unloading process is done by me.
Then I want to insert some filament and use the LCD prompt telling me to push the button for extrusion to start.

The prompt appears and I push the button aaaaaaaaaand.....nothing happens.
So I am stuck within a pause with a locked extruder motor and have to stop the whole print.

It is kind of annoying and I don't know where the problem is. Maybe I just can't get my head around how this feature is supposed to work but I have seen videos where this is done.

Can anyone help me?

Appreciation in advance.