fixed multiple value parser

Author: engcom-Charlie

app/code/Magento/CatalogImportExport/Model/Import/Product.php

@@ -46,6 +46,7 @@
  */
 class Product extends AbstractEntity
 {
+    private const DEFAULT_GLOBAL_MULTIPLE_VALUE_SEPARATOR = ',';
     public const CONFIG_KEY_PRODUCT_TYPES = 'global/importexport/import_product_types';
     private const HASH_ALGORITHM = 'sha256';
 
@@ -2841,6 +2842,10 @@ private function parseAttributesWithWrappedValues($attributesData)
     public function parseMultiselectValues($values, $delimiter = self::PSEUDO_MULTI_LINE_SEPARATOR)
     {
         if (empty($this->_parameters[Import::FIELDS_ENCLOSURE])) {
+            if ($this->getMultipleValueSeparator() !== self::DEFAULT_GLOBAL_MULTIPLE_VALUE_SEPARATOR) {
+                $delimiter = $this->getMultipleValueSeparator();
+            }
+
             return explode($delimiter, $values);
         }
         if (preg_match_all('~"((?:[^"]|"")*)"~', $values, $matches)) {

app/code/Magento/CatalogImportExport/Model/Import/Product/Validator.php

@@ -17,8 +17,6 @@
  */
 class Validator extends AbstractValidator implements RowValidatorInterface
 {
-    private const DEFAULT_GLOBAL_MULTIPLE_VALUE_SEPARATOR = ',';
-
     /**
      * @var RowValidatorInterface[]|AbstractValidator[]
      */
@@ -229,12 +227,7 @@ public function isAttributeValid($attrCode, array $attrParams, array $rowData)
                 $valid = $this->validateOption($attrCode, $attrParams['options'], $rowData[$attrCode]);
                 break;
             case 'multiselect':
-                $separator = $this->context->getMultipleValueSeparator();
-                // added to prevent backward compatibility since before we didn't use separator param value
-                $values = $separator === self::DEFAULT_GLOBAL_MULTIPLE_VALUE_SEPARATOR
-                    ? $this->context->parseMultiselectValues($rowData[$attrCode])
-                    : $this->context->parseMultiselectValues($rowData[$attrCode], $separator);
-
+                $values = $this->context->parseMultiselectValues($rowData[$attrCode]);
                 foreach ($values as $value) {
                     $valid = $this->validateOption($attrCode, $attrParams['options'], $value);
                     if (!$valid) {