Paper/paper-server/patches/sources/net/minecraft/server/commands/BanIpCommands.java.patch

--- a/net/minecraft/server/commands/BanIpCommands.java
+++ b/net/minecraft/server/commands/BanIpCommands.java
@@ -66,7 +66,7 @@
             }
 
             for (ServerPlayer serverPlayer : list) {
-                serverPlayer.connection.disconnect(Component.translatable("multiplayer.disconnect.ip_banned"));
+                serverPlayer.connection.disconnect(Component.translatable("multiplayer.disconnect.ip_banned"), org.bukkit.event.player.PlayerKickEvent.Cause.IP_BANNED); // Paper - kick event cause
             }
 
             return list.size();