diff --git a/Source/Game/Maps/Instances/InstanceScript.cs b/Source/Game/Maps/Instances/InstanceScript.cs
index 9cc4faa00..699895f9f 100644
--- a/Source/Game/Maps/Instances/InstanceScript.cs
+++ b/Source/Game/Maps/Instances/InstanceScript.cs
@@ -383,6 +383,8 @@ namespace Game.Maps
                             {
                                 DoUpdateCriteria(CriteriaType.DefeatDungeonEncounter, dungeonEncounter.Id);
                                 SendBossKillCredit(dungeonEncounter.Id);
+                                if (dungeonEncounter.CompleteWorldStateID != 0)
+                                    DoUpdateWorldState((uint)dungeonEncounter.CompleteWorldStateID, 1);
                             }
 
                             instance.DoOnPlayers(player => player.AtEndOfEncounter(EncounterType.DungeonEncounter));
@@ -448,9 +450,15 @@ namespace Game.Maps
                 // in loot-based lockouts instance can be loaded with later boss marked as killed without preceding bosses
                 // but we still need to have them alive
                 for (uint i = 0; i < bosses.Count; ++i)
+                {
                     if (bosses[i].state == EncounterState.Done && !CheckRequiredBosses(i))
                         bosses[i].state = EncounterState.NotStarted;
 
+                    var dungeonEncounter = bosses[i].GetDungeonEncounterForDifficulty(instance.GetDifficultyID());
+                    if (dungeonEncounter != null && dungeonEncounter.CompleteWorldStateID != 0)
+                        DoUpdateWorldState((uint)dungeonEncounter.CompleteWorldStateID, bosses[i].state == EncounterState.Done ? 1 : 0);
+                }
+
                 UpdateSpawnGroups();
                 AfterDataLoad();
             }
@@ -810,7 +818,6 @@ namespace Game.Maps
             {
                 if (encounter.creditType == type && encounter.creditEntry == creditEntry)
                 {
-                    completedEncounters |= (1u << encounter.dbcEntry.Bit);
                     if (encounter.dbcEntry.CompleteWorldStateID != 0)
                         DoUpdateWorldState((uint)encounter.dbcEntry.CompleteWorldStateID, 1);
 
@@ -840,19 +847,6 @@ namespace Game.Maps
             }
         }
 
-        public void SetCompletedEncountersMask(uint newMask)
-        {
-            completedEncounters = newMask;
-
-            var encounters = Global.ObjectMgr.GetDungeonEncounterList(instance.GetId(), instance.GetDifficultyID());
-            if (encounters != null)
-            {
-                foreach (DungeonEncounter encounter in encounters)
-                    if ((completedEncounters & (1 << encounter.dbcEntry.Bit)) != 0 && encounter.dbcEntry.CompleteWorldStateID != 0)
-                        DoUpdateWorldState((uint)encounter.dbcEntry.CompleteWorldStateID, 1);
-            }
-        }
-
         void UpdatePhasing()
         {
             instance.DoOnPlayers(player => PhasingHandler.SendToPlayer(player));
@@ -940,8 +934,6 @@ namespace Game.Maps
 
         public virtual bool CheckRequiredBosses(uint bossId, Player player = null) { return true; }
 
-        public uint GetCompletedEncounterMask() { return completedEncounters; }
-
         // Sets a temporary entrance that does not get saved to db
         public void SetTemporaryEntranceLocation(uint worldSafeLocationId) { _temporaryEntranceId = worldSafeLocationId; }
 
@@ -989,7 +981,6 @@ namespace Game.Maps
         Dictionary<uint, uint> _creatureInfo = new();
         Dictionary<uint, uint> _gameObjectInfo = new();
         Dictionary<uint, ObjectGuid> _objectGuids = new();
-        uint completedEncounters; // DEPRECATED, REMOVE
         List<InstanceSpawnGroupInfo> _instanceSpawnGroups = new();
         List<uint> _activatedAreaTriggers = new();
         uint _entranceId;
diff --git a/Source/Game/Maps/Map.cs b/Source/Game/Maps/Map.cs
index 213d8ae47..de74b0fc9 100644
--- a/Source/Game/Maps/Map.cs
+++ b/Source/Game/Maps/Map.cs
@@ -4889,7 +4889,6 @@ namespace Game.Maps
             }
 
             InstanceLockData lockData = i_instanceLock.GetInstanceInitializationData();
-            i_data.SetCompletedEncountersMask(lockData.CompletedEncountersMask);
             i_data.SetEntranceLocation(lockData.EntranceWorldSafeLocId);
             if (!lockData.Data.IsEmpty())
             {