diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82e40af9da..2bda796512 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fixed a bug where a Twig error would occur when creating or editing a shipping rule. ([#4321](https://github.com/craftcms/commerce/issues/4321))
+- Fixed a bug where settings weren’t being saved to the project config. ([#4324](https://github.com/craftcms/commerce/issues/4324))
 
 ## 5.6.6.1 - 2026-06-18
 
diff --git a/src/controllers/ProductTypesController.php b/src/controllers/ProductTypesController.php
index e943416e30..6f8700f4f9 100644
--- a/src/controllers/ProductTypesController.php
+++ b/src/controllers/ProductTypesController.php
@@ -144,6 +144,7 @@ public function actionSaveProductType(): ?Response
         $productType->hasDimensions = (bool)$this->request->getBodyParam('hasDimensions');
         $productType->hasProductTitleField = (bool)$this->request->getBodyParam('hasProductTitleField');
         $productType->productTitleFormat = $this->request->getBodyParam('productTitleFormat');
+        $productType->productUiLabelFormat = $this->request->getBodyParam('productUiLabelFormat');
         $productType->productTitleTranslationMethod = $this->request->getBodyParam('productTitleTranslationMethod', $productType->productTitleTranslationMethod);
         $productType->productTitleTranslationKeyFormat = $this->request->getBodyParam('productTitleTranslationKeyFormat', $productType->productTitleTranslationKeyFormat);
         $productType->showSlugField = (bool)$this->request->getBodyParam('showSlugField', $productType->showSlugField);
@@ -152,6 +153,7 @@ public function actionSaveProductType(): ?Response
         $productType->maxVariants = $this->request->getBodyParam('maxVariants') ?: null;
         $productType->hasVariantTitleField = $this->request->getBodyParam('hasVariantTitleField', false);
         $productType->variantTitleFormat = $this->request->getBodyParam('variantTitleFormat');
+        $productType->variantUiLabelFormat = $this->request->getBodyParam('variantUiLabelFormat');
         $productType->variantTitleTranslationMethod = $this->request->getBodyParam('variantTitleTranslationMethod', $productType->variantTitleTranslationMethod);
         $productType->variantTitleTranslationKeyFormat = $this->request->getBodyParam('variantTitleTranslationKeyFormat', $productType->variantTitleTranslationKeyFormat);
         $productType->skuFormat = $this->request->getBodyParam('skuFormat');
diff --git a/src/models/ProductType.php b/src/models/ProductType.php
index 2f71970083..5d34392b43 100644
--- a/src/models/ProductType.php
+++ b/src/models/ProductType.php
@@ -330,7 +330,7 @@ protected function defineRules(): array
             ['fieldLayout', 'validateFieldLayout'],
             ['variantFieldLayout', 'validateVariantFieldLayout'],
             ['siteSettings', 'required', 'message' => Craft::t('commerce','At least one site must be enabled for the product type.')],
-            [['isStructure', 'defaultPlacement', 'maxLevels', 'structureId'], 'safe'],
+            [['isStructure', 'defaultPlacement', 'maxLevels', 'structureId', 'productUiLabelFormat', 'variantUiLabelFormat'], 'safe'],
             [['previewTargets'], 'validatePreviewTargets'],
         ];
     }