diff --git a/bukkit/src/main/java/me/william278/husksync/bukkit/util/PlayerSetter.java b/bukkit/src/main/java/me/william278/husksync/bukkit/util/PlayerSetter.java
index 658dd54e..0800b250 100644
--- a/bukkit/src/main/java/me/william278/husksync/bukkit/util/PlayerSetter.java
+++ b/bukkit/src/main/java/me/william278/husksync/bukkit/util/PlayerSetter.java
@@ -162,18 +162,20 @@ public class PlayerSetter {
                             = DataSerializer.deserializeAdvancementData(data.getSerializedAdvancements());
 
                     if (Settings.useNativeImplementation) {
-                        try {
-                            nativeSyncPlayerAdvancements(player, advancementRecords);
-                        } catch (Exception e) {
-                            plugin.getLogger().log(Level.WARNING,
-                                    "Your server does not support a native implementation of achievements synchronization");
-                            plugin.getLogger().log(Level.WARNING,
-                                    "Your server version is {0}. Please disable using native implementation!", Bukkit.getVersion());
-
-                            Settings.useNativeImplementation = false;
-                            setPlayerAdvancements(player, advancementRecords, data);
-                            plugin.getLogger().log(Level.SEVERE, e.getMessage(), e);
-                        }
+                        Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
+                            try {
+                                nativeSyncPlayerAdvancements(player, advancementRecords);
+                            } catch (Exception e) {
+                                plugin.getLogger().log(Level.WARNING,
+                                        "Your server does not support a native implementation of achievements synchronization");
+                                plugin.getLogger().log(Level.WARNING,
+                                        "Your server version is {0}. Please disable using native implementation!", Bukkit.getVersion());
+
+                                Settings.useNativeImplementation = false;
+                                setPlayerAdvancements(player, advancementRecords, data);
+                                plugin.getLogger().log(Level.SEVERE, e.getMessage(), e);
+                            }
+                        });
                     } else {
                         setPlayerAdvancements(player, advancementRecords, data);
                     }
@@ -281,6 +283,7 @@ public class PlayerSetter {
 
         // Clear
         AdvancementUtils.clearPlayerAdvancementsMap(playerAdvancements);
+        AdvancementUtils.clearVisibleAdvancementsSet(playerAdvancements);
 
         advancementRecords.forEach(advancementRecord -> {
             NamespacedKey namespacedKey = Objects.requireNonNull(
@@ -306,8 +309,10 @@ public class PlayerSetter {
                 AdvancementUtils.startProgress(playerAdvancements, advancement, nativeAdvancementProgress);
             }
         });
-        AdvancementUtils.ensureAllVisible(playerAdvancements); // Set all completed advancement is visible
-        AdvancementUtils.markPlayerAdvancementsFirst(playerAdvancements); // Mark the sending of visible advancement as the first
+        synchronized (playerAdvancements) {
+            AdvancementUtils.ensureAllVisible(playerAdvancements); // Set all completed advancement is visible
+            AdvancementUtils.markPlayerAdvancementsFirst(playerAdvancements); // Mark the sending of visible advancement as the first
+        }
     }
 
     /**
diff --git a/bukkit/src/main/java/me/william278/husksync/bukkit/util/nms/AdvancementUtils.java b/bukkit/src/main/java/me/william278/husksync/bukkit/util/nms/AdvancementUtils.java
index a7b991fb..0fa6908e 100644
--- a/bukkit/src/main/java/me/william278/husksync/bukkit/util/nms/AdvancementUtils.java
+++ b/bukkit/src/main/java/me/william278/husksync/bukkit/util/nms/AdvancementUtils.java
@@ -9,19 +9,20 @@ import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Date;
 import java.util.Map;
+import java.util.Set;
 
 public class AdvancementUtils {
 
+    public final static Class<?> PLAYER_ADVANCEMENT;
     private final static Field PLAYER_ADVANCEMENTS_MAP;
+    private final static Field PLAYER_VISIBLE_ADVANCEMENTS_SET;
     private final static Field PLAYER_ADVANCEMENTS;
     private final static Field CRITERIA_MAP;
     private final static Field CRITERIA_DATE;
     private final static Field IS_FIRST_PACKET;
-
     private final static Method GET_HANDLE;
     private final static Method START_PROGRESS;
     private final static Method ENSURE_ALL_VISIBLE;
-
     private final static Class<?> ADVANCEMENT_PROGRESS;
     private final static Class<?> CRITERION_PROGRESS;
 
@@ -43,10 +44,13 @@ public class AdvancementUtils {
 
         Class<?> ADVANCEMENT = ThrowSupplier.get(() -> Class.forName("net.minecraft.advancements.Advancement"));
 
-        Class<?> PLAYER_ADVANCEMENT = MinecraftVersionUtils.getMinecraftClass("AdvancementDataPlayer");
+        PLAYER_ADVANCEMENT = MinecraftVersionUtils.getMinecraftClass("AdvancementDataPlayer");
         PLAYER_ADVANCEMENTS_MAP = ThrowSupplier.get(() -> PLAYER_ADVANCEMENT.getDeclaredField("h"));
         PLAYER_ADVANCEMENTS_MAP.setAccessible(true);
 
+        PLAYER_VISIBLE_ADVANCEMENTS_SET = ThrowSupplier.get(() -> PLAYER_ADVANCEMENT.getDeclaredField("i"));
+        PLAYER_VISIBLE_ADVANCEMENTS_SET.setAccessible(true);
+
         START_PROGRESS = ThrowSupplier.get(() -> PLAYER_ADVANCEMENT.getDeclaredMethod("a", ADVANCEMENT, ADVANCEMENT_PROGRESS));
         START_PROGRESS.setAccessible(true);
 
@@ -57,7 +61,7 @@ public class AdvancementUtils {
         IS_FIRST_PACKET.setAccessible(true);
     }
 
-    public static void markPlayerAdvancementsFirst(Object playerAdvancements) {
+    public static void markPlayerAdvancementsFirst(final Object playerAdvancements) {
         try {
             IS_FIRST_PACKET.set(playerAdvancements, true);
         } catch (IllegalAccessException e) {
@@ -130,4 +134,12 @@ public class AdvancementUtils {
         }
     }
 
+    public static void clearVisibleAdvancementsSet(final Object playerAdvancements) {
+        try {
+            ((Set<?>) PLAYER_VISIBLE_ADVANCEMENTS_SET.get(playerAdvancements))
+                    .clear();
+        } catch (IllegalAccessException e) {
+            throw new RuntimeException(e.getMessage(), e);
+        }
+    }
 }