diff --git a/front/src/applications/operationalStudies/hooks/useLazySimulateTrains.ts b/front/src/applications/operationalStudies/hooks/useLazySimulateTrains.ts
index 998e2f03255..1e7e58698b6 100644
--- a/front/src/applications/operationalStudies/hooks/useLazySimulateTrains.ts
+++ b/front/src/applications/operationalStudies/hooks/useLazySimulateTrains.ts
@@ -1,5 +1,6 @@
 import { useRef, useEffect, useCallback, useState } from 'react';
 
+import { osrdEditoastApi } from 'common/api/osrdEditoastApi';
 import type {
   LightRollingStockWithLiveries,
   TrainScheduleSimulationSummaryResult,
@@ -47,6 +48,7 @@ export default function useLazySimulateTrains({
   const [simulatedTrainsById, setSimulatedTrainsById] = useState<
     Map<number, TrainScheduleWithDetails>
   >(new Map());
+  const [allSimulationsDone, setAllSimulationsDone] = useState(false);
 
   const onProgressRef = useRef<UseLazySimulateTrainsOptions['onProgress']>(null);
   onProgressRef.current = onProgress;
@@ -54,6 +56,11 @@ export default function useLazySimulateTrains({
   useEffect(() => {
     if (!rollingStocks) return undefined;
 
+    const idsToSimulate = [...trainSchedulesByIdRef.current.keys()];
+    if (idsToSimulate.length > 0) {
+      setAllSimulationsDone(false);
+    }
+
     const loader = new TrainSimulationLazyLoader({
       dispatch,
       infraId,
@@ -67,10 +74,14 @@ export default function useLazySimulateTrains({
         );
         setSimulatedTrainsById((prev) => new Map([...prev.entries(), ...summaries.entries()]));
         if (onProgressRef.current) onProgressRef.current(summaries);
+        if (loader.pending.length === 0) {
+          setAllSimulationsDone(true);
+          dispatch(osrdEditoastApi.util.invalidateTags(['conflicts']));
+        }
       },
     });
 
-    loader.simulateTrainSchedules([...trainSchedulesByIdRef.current.keys()]);
+    loader.simulateTrainSchedules(idsToSimulate);
 
     loaderRef.current = loader;
     return () => {
@@ -84,6 +95,11 @@ export default function useLazySimulateTrains({
       trainSchedulesByIdRef.current.set(trainSchedule.id, trainSchedule);
     }
 
+    if (trainSchedules.length === 0) {
+      setAllSimulationsDone(true);
+      return;
+    }
+    setAllSimulationsDone(false);
     loaderRef.current?.simulateTrainSchedules(trainSchedules.map(({ id }) => id));
   }, []);
 
@@ -124,6 +140,6 @@ export default function useLazySimulateTrains({
     simulateTrainSchedules,
     removeSimulatedTrainSchedules,
     updateSimulatedTrainScheduleDepartureTime,
-    allTrainsSimulated: loaderRef.current && loaderRef.current.pending.length === 0,
+    allTrainsSimulated: allSimulationsDone,
   };
 }
diff --git a/front/src/applications/operationalStudies/hooks/useScenarioData.ts b/front/src/applications/operationalStudies/hooks/useScenarioData.ts
index 597e5025a6a..0b1c8165bf1 100644
--- a/front/src/applications/operationalStudies/hooks/useScenarioData.ts
+++ b/front/src/applications/operationalStudies/hooks/useScenarioData.ts
@@ -206,6 +206,7 @@ const useScenarioData = (scenario: ScenarioWithDetails, infraId: number, timetab
       }).unwrap();
 
       setTrainScheduleDepartureTime(trainScheduleId, newDeparture);
+      dispatch(osrdEditoastApi.util.invalidateTags(['conflicts']));
     },
     [trainSchedules]
   );
diff --git a/front/src/common/api/osrdEditoastApi.ts b/front/src/common/api/osrdEditoastApi.ts
index 14b0eaf0f12..ca55f1361e5 100644
--- a/front/src/common/api/osrdEditoastApi.ts
+++ b/front/src/common/api/osrdEditoastApi.ts
@@ -268,6 +268,7 @@ const osrdEditoastApi = generatedEditoastApi
     }),
   })
   .enhanceEndpoints({
+    addTagTypes: ['conflicts'] as const,
     endpoints: {
       getLightRollingStock: {
         transformResponse: (response: GetLightRollingStockApiResponse) => ({
@@ -281,8 +282,11 @@ const osrdEditoastApi = generatedEditoastApi
       // As we always use all get train_schedule endpoints after updating the timetable,
       // we don't want to invalidate the train_schedule tags here to prevent multiple calls
 
+      getTimetableByIdConflicts: {
+        providesTags: ['conflicts'],
+      },
       deleteTrainSchedules: {
-        invalidatesTags: ['timetable', 'scenarios'],
+        invalidatesTags: ['timetable', 'scenarios', 'conflicts'],
       },
       postTrainScheduleSetsByIdTrainSchedules: {
         invalidatesTags: ['train_schedule_set', 'scenarios', 'timetable'],