We can do this without needing a runnable.

src/main/java/com/gmail/nossr50/listeners/BlockListener.java

@@ -10,6 +10,7 @@ import org.bukkit.block.Block;
 import org.bukkit.block.BlockFace;
 import org.bukkit.block.BlockState;
 import org.bukkit.block.BrewingStand;
+import org.bukkit.block.PistonMoveReaction;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -31,7 +32,6 @@ import com.gmail.nossr50.datatypes.skills.SkillType;
 import com.gmail.nossr50.datatypes.skills.ToolType;
 import com.gmail.nossr50.events.fake.FakeBlockBreakEvent;
 import com.gmail.nossr50.events.fake.FakeBlockDamageEvent;
-import com.gmail.nossr50.runnables.StickyPistonTrackerTask;
 import com.gmail.nossr50.skills.alchemy.Alchemy;
 import com.gmail.nossr50.skills.excavation.ExcavationManager;
 import com.gmail.nossr50.skills.herbalism.HerbalismManager;
@@ -90,10 +90,18 @@ public class BlockListener implements Listener {
      */
     @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
     public void onBlockPistonRetract(BlockPistonRetractEvent event) {
-        if (event.isSticky()) {
-            // Needed only because under some circumstances Minecraft doesn't move the block
-            new StickyPistonTrackerTask(event.getDirection(), event.getBlock()).runTaskLater(plugin, 2);
+        if (!event.isSticky()) {
+            return;
+        }
+
+        Block movedBlock = event.getRetractLocation().getBlock();
+
+        if (movedBlock.getPistonMoveReaction() != PistonMoveReaction.MOVE || !mcMMO.getPlaceStore().isTrue(movedBlock)) {
+            return;
         }
+
+        mcMMO.getPlaceStore().setFalse(movedBlock);
+        mcMMO.getPlaceStore().setTrue(event.getBlock().getRelative(event.getDirection()));
     }
 
     /**

src/main/java/com/gmail/nossr50/runnables/StickyPistonTrackerTask.java

@@ -1,31 +0,0 @@
-package com.gmail.nossr50.runnables;
-
-import org.bukkit.Material;
-import org.bukkit.block.Block;
-import org.bukkit.block.BlockFace;
-import org.bukkit.scheduler.BukkitRunnable;
-
-import com.gmail.nossr50.mcMMO;
-
-public class StickyPistonTrackerTask extends BukkitRunnable {
-    private BlockFace direction;
-    private Block block;
-
-    public StickyPistonTrackerTask(BlockFace direction, Block block) {
-        this.direction = direction;
-        this.block = block;
-    }
-
-    @Override
-    public void run() {
-        Block newBlock = block.getRelative(direction);
-        Block originalBlock = newBlock.getRelative(direction);
-
-        if (originalBlock.getType() != Material.AIR || !mcMMO.getPlaceStore().isTrue(originalBlock)) {
-            return;
-        }
-
-        mcMMO.getPlaceStore().setFalse(originalBlock);
-        mcMMO.getPlaceStore().setTrue(newBlock);
-    }
-}