Cannot return null for non-nullable field SelectedCustomizableOptionV…

…alue.sort_order and Call to a member function getPriceType() on null

app/code/Magento/QuoteGraphQl/Model/Cart/AddSimpleProductToCart.php

@@ -170,7 +170,7 @@ private function createBuyRequest(float $quantity, array $customOptions): DataOb
      */
     private function convertCustomOptions(string $value)
     {
-        if (substr($value, 0, 1) === "[" ||
+        if (substr($value, 0, 1) === "[" &&
             substr($value, strlen($value) - 1, 1) === "]") {
             return explode(',', substr($value, 1, -1));
         }