How to use PilotedPOI

When I start the POI (with the StartPilotedPOI command) the PilotedPOI goes into the RUNNING state. But when I send a moveBy command, the drone does not move.

Here an example code that does not work:

from __future__ import print_function  # python2/3 compatibility for the print function
import olympe
from olympe.messages.ardrone3.PilotingState import PilotedPOI, FlyingStateChanged, PositionChanged
from olympe.messages.ardrone3.Piloting import TakeOff, StartPilotedPOI, moveBy, StopPilotedPOI
from olympe.messages.ardrone3.GPSSettingsState import GPSFixStateChanged
from olympe.messages.ardrone3.GPSSettingsState import GPSFixStateChanged, HomeChanged
from olympe.messages.ardrone3.PilotingEvent import moveByEnd
import time

# Connection
drone = olympe.Drone("")

# Wait for GPS fix
drone(GPSFixStateChanged(_policy = 'wait'))

# Take-off
    FlyingStateChanged(state="hovering", _policy="check")
    | FlyingStateChanged(state="flying", _policy="check")
    | (
        GPSFixStateChanged(fixed=1, _timeout=10, _policy="check_wait")
        >> (
            & FlyingStateChanged(
                state="hovering", _timeout=10, _policy="check_wait")

# Getting the GPS position
pos = drone.get_state(PositionChanged)
latitude = pos['latitude']
longitude = pos['longitude']
altitude = pos['altitude']

# Enabling the POI
    StartPilotedPOI(latitude, longitude, altitude)
    >> (PilotedPOI(latitude=latitude, longitude=longitude, altitude=altitude, status='RUNNING', _policy='wait') 
         PilotedPOI(latitude=latitude, longitude=longitude, altitude=altitude, status='PENDING', _policy='wait'))

# Moving the drone 
    moveBy(5, 5, 0, 0)
    >> moveByEnd(_policy='wait')


So, how PilotedPOI works?

Thank you