diff --git a/custom_components/versatile_thermostat/feature_window_manager.py b/custom_components/versatile_thermostat/feature_window_manager.py
index 8b036e9..2497e6a 100644
--- a/custom_components/versatile_thermostat/feature_window_manager.py
+++ b/custom_components/versatile_thermostat/feature_window_manager.py
@@ -281,6 +281,7 @@ class FeatureWindowManager(BaseFeatureManager):
                 _LOGGER.debug(
                     "%s is already off. Forget turning off VTherm due to window detection"
                 )
+                self._window_state = new_state
                 return False
 
             # self._window_state = new_state
@@ -537,7 +538,7 @@ class FeatureWindowManager(BaseFeatureManager):
     @property
     def last_slope(self) -> float:
         """Return the last slope (in °C/hour)"""
-        if not self.is_configured:
+        if not self._window_auto_algo:
             return None
         return self._window_auto_algo.last_slope
 
diff --git a/tests/test_auto_start_stop.py b/tests/test_auto_start_stop.py
index 212890b..d52ecba 100644
--- a/tests/test_auto_start_stop.py
+++ b/tests/test_auto_start_stop.py
@@ -1310,7 +1310,7 @@ async def test_auto_start_stop_fast_heat_window(
     # VTherm should be heating
     assert vtherm.hvac_mode == HVACMode.HEAT
     # VTherm window_state should be off
-    assert vtherm.window_state == STATE_OFF
+    assert vtherm.window_state == STATE_UNKNOWN  # cause condition is not evaluated
 
     # 3. Set current temperature to 21 5 min later -> should turn off VTherm
     now = now + timedelta(minutes=5)
@@ -1485,7 +1485,7 @@ async def test_auto_start_stop_fast_heat_window_mixed(
     # VTherm should be heating
     assert vtherm.hvac_mode == HVACMode.HEAT
     # VTherm window_state should be off
-    assert vtherm.window_state == STATE_OFF
+    assert vtherm.window_state == STATE_UNKNOWN  # cause try_condition is not evaluated
 
     # 3. Open the window and wait for the delay
     now = now + timedelta(minutes=2)
diff --git a/tests/test_central_config.py b/tests/test_central_config.py
index 02f0727..8491c36 100644
--- a/tests/test_central_config.py
+++ b/tests/test_central_config.py
@@ -282,11 +282,14 @@ async def test_full_over_switch_wo_central_config(
         assert (
             entity.window_manager.is_window_auto_configured is False
         )  # we have an entity_id
-        assert entity._window_sensor_entity_id == "binary_sensor.mock_window_sensor"
-        assert entity._window_delay_sec == 30
-        assert entity._window_auto_close_threshold == 0.1
-        assert entity._window_auto_open_threshold == 3
-        assert entity._window_auto_max_duration == 5
+        assert (
+            entity.window_manager._window_sensor_entity_id
+            == "binary_sensor.mock_window_sensor"
+        )
+        assert entity.window_manager.window_delay_sec == 30
+        assert entity.window_manager.window_auto_close_threshold == 0.1
+        assert entity.window_manager.window_auto_open_threshold == 3
+        assert entity.window_manager.window_auto_max_duration == 5
 
         assert (
             entity.motion_manager.motion_sensor_entity_id
@@ -405,11 +408,14 @@ async def test_full_over_switch_with_central_config(
 
         # We have an entity so window auto is not enabled
         assert entity.window_manager.is_window_auto_configured is False
-        assert entity._window_sensor_entity_id == "binary_sensor.mock_window_sensor"
-        assert entity._window_delay_sec == 15
-        assert entity._window_auto_close_threshold == 1
-        assert entity._window_auto_open_threshold == 4
-        assert entity._window_auto_max_duration == 31
+        assert (
+            entity.window_manager._window_sensor_entity_id
+            == "binary_sensor.mock_window_sensor"
+        )
+        assert entity.window_manager.window_delay_sec == 15
+        assert entity.window_manager.window_auto_close_threshold == 1
+        assert entity.window_manager.window_auto_open_threshold == 4
+        assert entity.window_manager.window_auto_max_duration == 31
 
         assert (
             entity.motion_manager.motion_sensor_entity_id
diff --git a/tests/test_multiple_switch.py b/tests/test_multiple_switch.py
index 5ea309e..08455ed 100644
--- a/tests/test_multiple_switch.py
+++ b/tests/test_multiple_switch.py
@@ -69,7 +69,7 @@ async def test_one_switch_cycle(
         assert entity.hvac_mode is HVACMode.HEAT
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_UNKNOWN
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
@@ -289,7 +289,7 @@ async def test_multiple_switchs(
         assert entity.hvac_mode is HVACMode.HEAT
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_OFF
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
@@ -426,7 +426,7 @@ async def test_multiple_climates(
         assert entity.hvac_mode is HVACMode.HEAT
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_OFF
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
@@ -451,7 +451,7 @@ async def test_multiple_climates(
         assert entity.hvac_mode is HVACMode.OFF
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_OFF
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
@@ -527,7 +527,7 @@ async def test_multiple_climates_underlying_changes(
         assert entity.hvac_mode is HVACMode.HEAT
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_OFF
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
@@ -672,7 +672,7 @@ async def test_multiple_climates_underlying_changes_not_aligned(
         assert entity.hvac_mode is HVACMode.HEAT
         assert entity.preset_mode is PRESET_BOOST
         assert entity.target_temperature == 19
-        assert entity.window_state is STATE_OFF
+        assert entity.window_state is STATE_UNAVAILABLE
 
         event_timestamp = now - timedelta(minutes=4)
         await send_temperature_change_event(entity, 15, event_timestamp)
diff --git a/tests/test_overclimate.py b/tests/test_overclimate.py
index 49b3e9d..30581a2 100644
--- a/tests/test_overclimate.py
+++ b/tests/test_overclimate.py
@@ -960,7 +960,7 @@ async def test_manual_hvac_off_should_take_the_lead_over_window(
     # VTherm should be heating
     assert vtherm.hvac_mode == HVACMode.HEAT
     # VTherm window_state should be off
-    assert vtherm.window_state == STATE_OFF
+    assert vtherm.window_state == STATE_UNKNOWN  # Cause try_condition is not called
 
     # 2. Open the window and wait for the delay
     now = now + timedelta(minutes=2)
diff --git a/tests/test_overclimate_valve.py b/tests/test_overclimate_valve.py
index 57d28f1..131460c 100644
--- a/tests/test_overclimate_valve.py
+++ b/tests/test_overclimate_valve.py
@@ -112,7 +112,7 @@ async def test_over_climate_valve_mono(hass: HomeAssistant, skip_hass_states_get
         ]
         assert vtherm.preset_mode is PRESET_NONE
         assert vtherm._security_state is False
-        assert vtherm._window_state is None
+        assert vtherm.window_state is STATE_UNAVAILABLE
         assert vtherm.motion_state is STATE_UNAVAILABLE
         assert vtherm.presence_state is STATE_UNAVAILABLE
 
diff --git a/tests/test_start.py b/tests/test_start.py
index d9c6175..16e5d19 100644
--- a/tests/test_start.py
+++ b/tests/test_start.py
@@ -54,7 +54,7 @@ async def test_over_switch_full_start(hass: HomeAssistant, skip_hass_states_is_s
         ]
         assert entity.preset_mode is PRESET_NONE
         assert entity._security_state is False
-        assert entity._window_state is None
+        assert entity.window_state is STATE_UNKNOWN
         assert entity.motion_state is STATE_UNKNOWN
         assert entity.presence_state is STATE_UNKNOWN
         assert entity._prop_algorithm is not None
@@ -113,7 +113,7 @@ async def test_over_climate_full_start(hass: HomeAssistant, skip_hass_states_is_
         ]
         assert entity.preset_mode is PRESET_NONE
         assert entity._security_state is False
-        assert entity._window_state is None
+        assert entity.window_state is STATE_UNAVAILABLE
         assert entity.motion_state is STATE_UNAVAILABLE
         assert entity.presence_state is STATE_UNAVAILABLE
         assert entity.have_valve_regulation is False
@@ -169,7 +169,7 @@ async def test_over_4switch_full_start(hass: HomeAssistant, skip_hass_states_is_
         ]
         assert entity.preset_mode is PRESET_NONE
         assert entity._security_state is False
-        assert entity._window_state is None
+        assert entity.window_state is STATE_UNKNOWN
         assert entity.motion_state is STATE_UNKNOWN
         assert entity.presence_state is STATE_UNKNOWN
         assert entity._prop_algorithm is not None
diff --git a/tests/test_switch_ac.py b/tests/test_switch_ac.py
index a5a11ae..4fc8b09 100644
--- a/tests/test_switch_ac.py
+++ b/tests/test_switch_ac.py
@@ -90,8 +90,8 @@ async def test_over_switch_ac_full_start(
         ]
         assert entity.preset_mode is PRESET_NONE
         assert entity._security_state is False  # pylint: disable=protected-access
-        assert entity._window_state is None  # pylint: disable=protected-access
-        assert entity.motion_state is STATE_UNKNOWN  # pylint: disable=protected-access
+        assert entity.window_state is STATE_UNKNOWN
+        assert entity.motion_state is STATE_UNKNOWN
         assert entity.presence_state is STATE_UNKNOWN
         assert entity._prop_algorithm is not None  # pylint: disable=protected-access
 
diff --git a/tests/test_valve.py b/tests/test_valve.py
index 5cfa843..eb6f186 100644
--- a/tests/test_valve.py
+++ b/tests/test_valve.py
@@ -99,8 +99,8 @@ async def test_over_valve_full_start(
         ]
         assert entity.preset_mode is PRESET_NONE
         assert entity._security_state is False  # pylint: disable=protected-access
-        assert entity._window_state is None  # pylint: disable=protected-access
-        assert entity.motion_state is STATE_UNKNOWN  # pylint: disable=protected-access
+        assert entity.window_state is STATE_UNKNOWN
+        assert entity.motion_state is STATE_UNKNOWN
         assert entity.presence_state is STATE_UNKNOWN
         assert entity._prop_algorithm is not None  # pylint: disable=protected-access
         assert entity.have_valve_regulation is False