fix: regression introduced in my previous commit + add guard

src/CFBG.cpp

@@ -5,12 +5,11 @@
  */
 
 #include "CFBG.h"
-#include "BattlegroundMgr.h"
+#include "BattlegroundQueue.h"
 #include "BattlegroundUtils.h"
 #include "Chat.h"
 #include "Config.h"
 #include "Containers.h"
-#include "GroupMgr.h"
 #include "Language.h"
 #include "Log.h"
 #include "Opcodes.h"
@@ -403,6 +402,17 @@ void CFBG::BalanceTeamsOnEntry(Battleground* bg, Player* player)
     if (bg->GetPlayers().find(player->GetGUID()) != bg->GetPlayers().end())
         return;
 
+    // Never flip a player who is already faked. The faction sync that backs
+    // GetTeamId() -- SetFakeRaceAndMorph -> SetFactionForRace -> setTeamId() -- is
+    // skipped for already-faked players (its IsPlayerFake guard). Flipping bgTeamId
+    // now would therefore move the player to the new side for grouping/graveyards/
+    // win purposes while GetTeamId() (used by flag capture and scoring) stays on the
+    // OLD side -- e.g. an Alliance player on Horde's side capturing Alliance flags.
+    // Fresh entrants are not faked yet (the morph runs right after this), so they
+    // are still rebalanced normally.
+    if (IsPlayerFake(player))
+        return;
+
     TeamId provisional = player->GetBgTeamId();
 
     // Live head counts correctly EXCLUDE the entering player (counted later in

src/CFBG_SC.cpp

@@ -148,6 +148,15 @@ class CFBG_Player : public PlayerScript
         if (!sCFBG->IsPlayerFake(player))
             return;
 
+        // Battleground fakes are owned by the BG hooks (OnBattlegroundRemovePlayerAtLeave
+        // / OnBattlegroundEndReward), not this WG cleanup. A battleground zone is not a
+        // WG battlefield, so without this guard entering a BG would clear a cross-faction
+        // player's fake right after the entry morph (Battleground::AddPlayer runs before
+        // UpdateZone), leaving GetTeamId() on the real faction while bgTeamId stays on the
+        // assigned side -- the flag-capture/win desync. WG players are not InBattleground().
+        if (player->InBattleground())
+            return;
+
         Battlefield* bf = sBattlefieldMgr->GetBattlefieldToZoneId(newZone);
         if (!bf || bf->GetTypeId() != BATTLEFIELD_WG)
             sCFBG->ClearFakePlayer(player);