Item fails to pop?

I have the following code for a Crates plugin:

PHP:

<?php
namespace jasonwynn10\Crates;

use pocketmine\block\Chest;
use pocketmine\event\block\BlockPlaceEvent;
use pocketmine\event\inventory\InventoryOpenEvent;
use pocketmine\event\Listener;
use pocketmine\item\Item;
use pocketmine\level\Position;
use pocketmine\nbt\JsonNBTParser;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\tag\StringTag;
use pocketmine\plugin\Plugin;
use pocketmine\plugin\PluginBase;
use pocketmine\scheduler\PluginTask;
use pocketmine\utils\Config;

class Main extends PluginBase implements Listener {
    public function onEnable() {
        @mkdir($this->getDataFolder());
        new Config($this->getDataFolder()."config.yml",Config::YAML, [
            "Spirit" => [
                "stick 2 {display:{Name:\"§r§6§lNormal stick\"}}",
                "diamond_sword 1",
                "wool:4 3"
            ],
            "Paranormal" => ["stick 1 {ench:[{id:12s,lvl:10s}]}"],
            "Psycho" => ["stick 1 {display:{Name:\"§eTHE POWER\"},ench:[{id:12s,lvl:50s}]}"],
            "Reaper" => ["stick 1 {display:{Name:\"§eTHE POWER\"},ench:[{id:12s,lvl:50s}]}"],
            "DemonLord" => ["stick 1 {display:{Name:\"§eTHE POWER\"},ench:[{id:12s,lvl:50s}]}"]
        ]);
        $this->getConfig()->reload();
        $this->getServer()->getPluginManager()->registerEvents($this, $this);
    }

    /**
     * @param string $crate
     *
     * @return Item[]
     */
    public function getRandomItems(string $crate) : array {
        $items = [];
        foreach($this->getConfig()->get($crate, []) as $itemString) {
            $arr = explode(" ", $itemString);
            $item = Item::fromString($arr[0]);
            if(!isset($arr[1])) {
                $item->setCount($item->getMaxStackSize());
            }else{
                $item->setCount((int) $arr[1]);
            }
            if(isset($arr[2])) {
                $tags = $exception = null;
                $data = implode(" ", array_slice($arr, 2));
                try{
                    $tags = JsonNBTParser::parseJSON($data);
                }catch(\Throwable $ex) {
                    $exception = $ex;
                }
                if(!$tags instanceof CompoundTag or $exception !== null) {
                    $this->getLogger()->error("Invalid NBT tag!");
                    continue;
                }
                $item->setNamedTag($tags);
            }
            $items[] = $item;
        }
        $randomised[10] = $items[array_rand($items)]; // randomize item given
        return $randomised;
    }
    public function onPlace(BlockPlaceEvent $event) {
        if($event->getBlock() instanceof Chest) {
            $this->getServer()->getScheduler()->scheduleDelayedTask(new class($this, $event->getBlock()->asPosition()) extends PluginTask {
                /** @var Position $coords */
                private $coords;
                public function __construct(Plugin $owner, Position $coords) {
                    parent::__construct($owner);
                    $this->coords = $coords;
                }
                public function onRun(int $currentTick) {
                    /** @var \pocketmine\tile\Chest|null $tile */
                    $tile = $this->coords->getLevel()->getTile($this->coords);
                    if(in_array($tile->getName(), $this->getOwner()->getConfig()->getAll(true))) {
                        $tile->namedtag->Lock = new StringTag("Lock", $tile->getName());
                    }
                }
            }, 1); // 1 tick delay
        }
    }
    public function onInventoryOpen(InventoryOpenEvent $ev) {
        $chestTile = $ev->getInventory()->getHolder();
        if($chestTile instanceof \pocketmine\tile\Chest and in_array($chestTile->getName(), $this->getConfig()->getAll(true))) {
            $inventory = $ev->getPlayer()->getInventory();
            $item = $inventory->getItemInHand();
            if($item->getId() === Item::TRIPWIRE_HOOK and $item->getName() === $chestTile->getName()) {
                $chest = $chestTile->getInventory();
                if(count($chest->getViewers()) > 0) {
                    $ev->setCancelled();
                    $ev->getPlayer()->sendMessage("This Crate is already in use!");
                    return;
                }
                $items = $this->getRandomItems($chestTile->getName());
                $ev->getInventory()->setContents($items);
                $item->pop();
                $inventory->setItem($inventory->getHeldItemIndex(), $item);
            }else{
                $ev->setCancelled();
            }
        }
    }
}

The error being experienced is that when the chest is tapped, the item fails to be removed from the stack/inventory. Any help is greatly appreciated.