src/de/steamwar/bungeecore/BungeeCore.java

@@ -158,6 +158,7 @@ public class BungeeCore extends Plugin {
         new SessionManager();
         new SpigotReceiver();
         new TablistManager();
+        new SettingsChangedListener();
 
         getProxy().getScheduler().schedule(this, () -> {
             SteamwarUser.clearCache();

src/de/steamwar/bungeecore/listeners/ConnectionListener.java

@@ -61,6 +61,14 @@ public class ConnectionListener extends BasicListener {
         ProxiedPlayer player = event.getPlayer();
         SteamwarUser user = SteamwarUser.get(player.getUniqueId());
 
+        if (!user.isManualLocale()) {
+            Locale locale = player.getLocale();
+            if (locale == null) {
+                locale = Locale.getDefault();
+            }
+            user.setLocale(locale, false);
+        }
+
         player.removeGroups("Admin", "team");
 
         if(user.getUserGroup().isAdminGroup())

src/de/steamwar/bungeecore/listeners/SettingsChangedListener.java

@@ -0,0 +1,46 @@
+/*
+ * This file is a part of the SteamWar software.
+ *
+ * Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.bungeecore.listeners;
+
+import de.steamwar.bungeecore.sql.SteamwarUser;
+import net.md_5.bungee.api.connection.ProxiedPlayer;
+import net.md_5.bungee.api.event.SettingsChangedEvent;
+import net.md_5.bungee.event.EventHandler;
+
+import java.util.Locale;
+
+public class SettingsChangedListener extends BasicListener {
+
+    @EventHandler
+    public void onSettingsChanged(SettingsChangedEvent event) {
+        ProxiedPlayer player = event.getPlayer();
+        SteamwarUser steamwarUser = SteamwarUser.get(player);
+
+        if (steamwarUser.isManualLocale())
+            return;
+
+        Locale locale = player.getLocale();
+        if (locale == null) {
+            locale = Locale.getDefault();
+        }
+
+        steamwarUser.setLocale(locale, false);
+    }
+}

src/de/steamwar/bungeecore/sql/SteamwarUser.java

@@ -389,9 +389,13 @@ public class SteamwarUser {
     }
 
     public void setLocale(Locale locale, boolean manualLocale) {
+        if (this.locale.equals(locale) && this.manualLocale == manualLocale)
+            return;
+        boolean needsUpdate = !this.locale.equals(locale);
         this.locale = locale;
         this.manualLocale = manualLocale;
         updateLocale.update(locale.getLanguage(), manualLocale, id);
-        new LocaleInvalidationPacket(id).send(getPlayer());
+        if (needsUpdate)
+            new LocaleInvalidationPacket(id).send(getPlayer());
     }
 }