force save all when owner has new site ids

Author: i-just

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Fixed a bug where multi-site elements’ search indexes could be updated twice.
 - Fixed a bug where the `utils/delete-empty-volume-folders` command was deleting folders that had no assets directly, but had subfolders. ([#16388](https://github.com/craftcms/cms/issues/16388))
+- Fixed a bug where some Matrix blocks weren’t getting propagated to newly-added sites of their owners, if any blocks had been modified. ([#16640](https://github.com/craftcms/cms/issues/16640))
 - Fixed a potential phishing attack vector.
 
 ## 4.14.4 - 2025-02-04

src/services/Matrix.php

@@ -693,7 +693,7 @@ public function saveField(MatrixField $field, ElementInterface $owner): void
         } else {
             $blocks = $value->getCachedResult();
             if ($blocks !== null) {
-                $saveAll = false;
+                $saveAll = !empty($owner->newSiteIds);
             } else {
                 $blocks = (clone $value)->status(null)->all();
                 $saveAll = true;