Try this.
Index: java/org/l2jmobius/gameserver/ai/PlayerAI.java
===================================================================
--- java/org/l2jmobius/gameserver/ai/PlayerAI.java (revision 9405)
+++ java/org/l2jmobius/gameserver/ai/PlayerAI.java (working copy)
@@ -298,6 +298,16 @@
clientStopMoving(null);
}
+ // Check if target has changed.
+ final WorldObject currentTarget = _actor.getTarget();
+ if ((currentTarget != target) && (currentTarget != null) && (target != null))
+ {
+ _actor.setTarget(target);
+ _actor.doCast(_skill);
+ _actor.setTarget(currentTarget);
+ return;
+ }
+
_actor.doCast(_skill);
}