@Z750 There are other command block types

Blocks.dc and .dd (don't know why they ain't renamed yet).
cc GH-478

Spigot-Server-Patches/0182-Filter-bad-data-from-ArmorStand-and-SpawnEgg-items.patch

@@ -1,4 +1,4 @@
-From 27f801bd116e4387e6b7b1696b23adf140940e4a Mon Sep 17 00:00:00 2001
+From 2693dcda742dac4a8ffd686a0cd52fddd36c5449 Mon Sep 17 00:00:00 2001
 From: Zach Brown <zach.brown@destroystokyo.com>
 Date: Sat, 12 Nov 2016 23:25:22 -0600
 Subject: [PATCH] Filter bad data from ArmorStand and SpawnEgg items
@@ -22,15 +22,17 @@ index 9d361cb..651f23e 100644
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/EntityFallingBlock.java b/src/main/java/net/minecraft/server/EntityFallingBlock.java
-index dcfdd31..f62fdde 100644
+index dcfdd31..abc4b5c 100644
 --- a/src/main/java/net/minecraft/server/EntityFallingBlock.java
 +++ b/src/main/java/net/minecraft/server/EntityFallingBlock.java
-@@ -250,6 +250,12 @@ public class EntityFallingBlock extends Entity {
+@@ -250,6 +250,14 @@ public class EntityFallingBlock extends Entity {
              this.block = Block.getById(nbttagcompound.getByte("Tile") & 255).fromLegacyData(i);
          }
  
 +        // Paper start - Block FallingBlocks with Command Blocks
-+        if (this.world.paperConfig.filterNBTFromSpawnEgg && this.block.getBlock() == Blocks.COMMAND_BLOCK) {
++        // Check mappings on update - dc = "repeating_command_block" - dd = "chain_command_block"
++        final Block b = this.block.getBlock();
++        if (this.world.paperConfig.filterNBTFromSpawnEgg && (b == Blocks.COMMAND_BLOCK || b == Blocks.dc || b == Blocks.dd)) {
 +            this.block = Blocks.STONE.getBlockData();
 +        }
 +        // Paper end