Magento inventory: Quantity source reduces by 2 instead of 1

Question

I am creating a shipment programatically. When an order is placed for the product, at order completion, quantity per source gets reduced by 2 instead of 1.

Here's my code

if($this->order->hasShipments()){
            return;
        }

        $shipment = $this->convertOrder->toShipment($this->order);


    foreach($this->order->getAllItems() as $orderItem){

        $qtyShipped = $orderItem->getQtyToShip() == 0 ? 1 : $orderItem->getQtyToShip() ;
        $shipmentItem = $this->convertOrder->itemToShipmentItem($orderItem)->setQty($qtyShipped);
        $shipment->addItem($shipmentItem);
    }

    $shipment->register();

    $shipment->getOrder()->setIsInProcess(true);

        $websiteId = $order->getStore()->getWebsiteId();
        $stockId = $this->stockByWebsiteIdResolver->execute((int)$websiteId)->getStockId();
        $sources = $this->getSourcesAssignedToStockOrderedByPriority->execute((int)$stockId);

        foreach ($sources as $source) {
            $sourceCode = $source->getSourceCode();
        }

       $shipmentExtension = $shipment->getExtensionAttributes();


    if (empty($shipmentExtension)) {
        $shipmentExtension = $this->shipmentExtensionFactory->create();
    }
    $shipmentExtension->setSourceCode($sourceCode);
    $shipment->setExtensionAttributes($shipmentExtension);

 $shipment->save();

Thanks!