From a2db5f0d6743f7ecb2f0ccba5a49e844affd8681 Mon Sep 17 00:00:00 2001
From: Andreas von Studnitz <avs@avs-webentwicklung.de>
Date: Tue, 17 Oct 2023 11:32:05 +0200
Subject: [PATCH] Fix customer group extension attributes

This plugin always created a new extension object, regardless of if one already exists. So it overwrote other extension attributes. This change checks if an extension object already exists.
---
 .../Model/Plugin/GetListCustomerGroupExcludedWebsite.php     | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/code/Magento/Customer/Model/Plugin/GetListCustomerGroupExcludedWebsite.php b/app/code/Magento/Customer/Model/Plugin/GetListCustomerGroupExcludedWebsite.php
index a3adb28da5b4..c856957608f0 100644
--- a/app/code/Magento/Customer/Model/Plugin/GetListCustomerGroupExcludedWebsite.php
+++ b/app/code/Magento/Customer/Model/Plugin/GetListCustomerGroupExcludedWebsite.php
@@ -64,7 +64,10 @@ public function afterGetList(
                     $customerGroupId = (int)$customerGroup->getId();
                     if (array_key_exists($customerGroupId, $allExcludedWebsites)) {
                         $excludedWebsites = $allExcludedWebsites[$customerGroupId];
-                        $customerGroupExtensionAttributes = $this->groupExtensionInterfaceFactory->create();
+                        $customerGroupExtensionAttributes = $customerGroup->getExtensionAttributes();
+                        if ($customerGroupExtensionAttributes === null) {
+                            $customerGroupExtensionAttributes = $this->groupExtensionInterfaceFactory->create();
+                        }
                         $customerGroupExtensionAttributes->setExcludeWebsiteIds($excludedWebsites);
                         $customerGroup->setExtensionAttributes($customerGroupExtensionAttributes);
                     }