I can't update sign

I have stored the poster that the last user click with a HashMap, and trying to finish the game update the poster, but not updated. However in the course of the game if that I've been able to update the poster.
I call the CheckWaves function from the EntityDeathEvent. I think that it will be for this reason, although I can't find a solution

Can that be?

Code:java

Map<Integer, Sign> Signs = new HashMap<Integer, Sign>();

Code:java

//-----------------------------------------------------------------------------------------------------------------------
public void CheckWaves(int game) {
 
if(VILLAGE_VILLAGERS[game] == 0) {
for(Player player : Bukkit.getOnlinePlayers()) {
if(GamePlayers[game].contains(player.getName())) {
player.teleport(new Location(player.getWorld(), SPAWN[0], SPAWN[1], SPAWN[2]));
 
 
VILLAGE_PLAYERS[game] = 0;
 
//UPDATE SIGN
System.out.println(Signs.get(game).getLine(0));
Signs.get(game).setLine(1, ChatColor.GREEN + "Lobby");
Signs.get(game).setLine(2, ChatColor.GREEN + "" + VILLAGE_PLAYERS[game] + "/" + VILLAGE_MAX_PLAYERS + " players");
Signs.get(game).update();
 
player.sendMessage("[VILLAGE] You have not saved the villagers");
}
}
 
} else if(VILLAGE_ZOMBIES[game] == 0) {
VILLAGE_WAVE[game]++;
startWave(game);
}
}