Magento 2 overriding ui component product form xml issue

Question

I have applied this solution for adding value to the input https://magento.stackexchange.com/questions/236797/set-default-value-for-date-in-ui-component

but I have two issues

here is my code:

    <?php

namespace Bnaia\SkuVendor\Ui\Component\Form\Element;

use Magento\Framework\App\Request\Http;
use Magento\Catalog\Api\ProductRepositoryInterface;
use Vnecoms\Vendors\Model\Session;

class Input extends \Magento\Ui\Component\Form\Element\Input
{
    protected $_vendorSession;
    protected $_urlInterface;
    protected $_product;
    public function __construct(
        \Magento\Framework\View\Element\UiComponent\context $context,
        Http $urlInterface,
        ProductRepositoryInterface $productRepository,
        Session $vendorSession
    ) {
        $this->_vendorSession = $vendorSession;
        $this->_urlInterface = $urlInterface;
        $this->_productRepository = $productRepository;
        parent::__construct($context);
    }
    public function prepare()
    {

        parent::prepare();
        $vendorId = $this->_vendorSession->getVendor()->getVendorId();
        $product_id = $this->_urlInterface->getParam('id');
        $product = $this->_productRepository->getById($product_id);
        $sku = $product->getSku();
        $config = $this->getData('config');
        \Magento\Framework\App\ObjectManager::getInstance()
            ->get(\Psr\Log\LoggerInterface::class)->debug('message ' . print_r($sku . '_' .$vendorId,true));

        if(isset($config['dataScope']) && $config['dataScope']=='sku'){
            $config['default']= $sku .'_'. $vendorId;
            $this->setData('config', (array)$config);
        }
    }
}

first: when I used constructor to use methods from other modules the input filed disappeared. but It didn't disappear when I have used the same methods using objectmanager

this is sample of working code

    <?php

namespace Bnaia\SkuVendor\Ui\Component\Form\Element;
//use Vnecoms\Vendors\Model\Session;

class Input extends \Magento\Ui\Component\Form\Element\Input
{

    public function prepare()
    {
        parent::prepare();
        $urlInterface = \Magento\Framework\App\ObjectManager::getInstance()->get('Magento\Framework\App\Request\Http');
        $vendorIds = \Magento\Framework\App\ObjectManager::getInstance()->get('Vnecoms\Vendors\Model\Session');
        $vendor = $vendorIds->getVendor();
        $product_id = $urlInterface->getParam('id');
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $product = $objectManager->create('Magento\Catalog\Model\Product')->load($product_id);
        $sku = $product->getSku();
        $vendorId = $product->getVendorId();
        $config = $this->getData('config');
        \Magento\Framework\App\ObjectManager::getInstance()
            ->get(\Psr\Log\LoggerInterface::class)->debug('message' . print_r( ' test '. $vendor .  $vendorId,true));

        if(isset($config['dataScope']) && $config['dataScope']=='sku'){
            $config['default']= $sku .'_' ;
            $this->setData('config', (array)$config);
        }
    }
}

and as we know using object manager is not recommended calling a class methods.

second issue.

I got the SKU input duplicated I can't override the existing sku input value

here is the xml form

    <?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">

    <fieldset name="product-details">
        <field name="sku" formElement="input">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="class" xsi:type="string">Bnaia\SkuVendor\Ui\Component\Form\Element\Input</item>
                    <item name="sortOrder" xsi:type="number">10</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="label" xsi:type="string" translate="true">SKU</item>
                    <item name="dataScope" xsi:type="string">sku</item>
                    <item name="scopeLabel" xsi:type="string">[GLOBAL]</item>
                </item>
            </argument>
        </field>

    </fieldset>
</form>

I need guide thanks for help.