Fixed issue with tier price issue

Author: Usik2203

app/code/Magento/CatalogCustomerGraphQl/Model/Resolver/PriceTiers.php

@@ -19,7 +19,6 @@
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
 use Magento\Framework\Pricing\PriceCurrencyInterface;
-use Magento\Store\Api\Data\StoreInterface;
 
 /**
  * Resolver for price_tiers
@@ -125,6 +124,10 @@ public function resolve(
             return [];
         }
 
+        if (!$product->getTierPrices()) {
+            return [];
+        }
+
         $productId = (int)$product->getId();
         $this->tiers->addProductFilter($productId);
 
@@ -152,7 +155,7 @@ private function formatAndFilterTierPrices(
         array $tierPrices,
         string $currencyCode
     ): array {
-
+        $this->resetFormatAndFilterTierPrices();
         foreach ($tierPrices as $key => $tierPrice) {
             $tierPrice->setValue($this->priceCurrency->convertAndRound($tierPrice->getValue()));
             $this->formatTierPrices($productPrice, $currencyCode, $tierPrice);
@@ -212,4 +215,14 @@ private function filterTierPrices(
             $this->tierPricesQty[$qty] = $key;
         }
     }
+
+    /**
+     *  Remove all element from formatAndFilterTierPrices
+     */
+    private function resetFormatAndFilterTierPrices()
+    {
+        foreach ($this->formatAndFilterTierPrices as $key => $value) {
+            unset($this->formatAndFilterTierPrices[$key]);
+        }
+    }
 }