diff --git a/wordpress/themes/cdcf-headless/includes/admin/submission-lifecycle.php b/wordpress/themes/cdcf-headless/includes/admin/submission-lifecycle.php
index 766e470..18db2c9 100644
--- a/wordpress/themes/cdcf-headless/includes/admin/submission-lifecycle.php
+++ b/wordpress/themes/cdcf-headless/includes/admin/submission-lifecycle.php
@@ -456,6 +456,18 @@ function cdcf_repend_submission_on_untrash($new_status, $old_status, $post): voi
  * Only acts on the English source post — when the worker promotes
  * a translation sibling to publish, this hook fires again, but
  * there's nothing more to enqueue at that point.
+ *
+ * The actual enqueue work is deferred to `shutdown` rather than run
+ * synchronously here. Running it inline puts our nested wp_insert_post
+ * + pll_save_post_translations calls inside Polylang's own save_post
+ * chain for the source post (and each freshly-inserted draft), where
+ * the multi-post group save silently fails to persist. Observed on
+ * production 2026-06-16: FamilyGraph submission 1381 was published
+ * with EN/IT/ES/FR/PT/DE siblings created and worker-translated, but
+ * the Polylang translation group came out empty on all six posts and
+ * Phase 0's attachment translation siblings were never created. The
+ * identical pll_save_post_translations call from outside the save
+ * chain (via /cdcf/v1/link-translations) persisted on the first try.
  */
 function cdcf_enqueue_translations_on_publish($new_status, $old_status, $post): void {
     if ($new_status === $old_status) {
@@ -480,7 +492,10 @@ function cdcf_enqueue_translations_on_publish($new_status, $old_status, $post):
         return;
     }
 
-    cdcf_enqueue_translations_for_submission($source_id, $post->post_type);
+    $post_type = $post->post_type;
+    add_action('shutdown', static function () use ($source_id, $post_type): void {
+        cdcf_enqueue_translations_for_submission($source_id, $post_type);
+    });
 }
 
 /**
diff --git a/wordpress/themes/cdcf-headless/tests/SubmissionLifecycleTest.php b/wordpress/themes/cdcf-headless/tests/SubmissionLifecycleTest.php
index 5ecd7a2..9e9727f 100644
--- a/wordpress/themes/cdcf-headless/tests/SubmissionLifecycleTest.php
+++ b/wordpress/themes/cdcf-headless/tests/SubmissionLifecycleTest.php
@@ -886,8 +886,20 @@ public function test_publish_hook_skips_non_public_submission_posts(): void
         $this->assertTrue(true);
     }
 
-    public function test_publish_hook_enqueues_translations_for_public_submission(): void
+    public function test_publish_hook_defers_enqueue_to_shutdown_for_public_submission(): void
     {
+        // The publish hook MUST defer cdcf_enqueue_translations_for_submission to
+        // the `shutdown` action — running it synchronously inside
+        // transition_post_status puts our pll_save_post_translations call inside
+        // Polylang's own nested save_post chain for the source post + each
+        // freshly-inserted draft, which silently drops the multi-post group save.
+        //
+        // Observed in production 2026-06-16: FamilyGraph submission 1381 was
+        // published with EN/IT/ES/FR/PT/DE siblings created and worker-translated,
+        // but the Polylang group came out empty on all six posts AND Phase 0's
+        // attachment translation siblings were never created. Re-running the
+        // identical pll_save_post_translations call from outside the save chain
+        // (via /cdcf/v1/link-translations) persisted on the first attempt.
         $this->stubCommonFunctions();
         Functions\when('pll_get_post')->justReturn(0); // self-source
         Functions\when('get_post_meta')->alias(
@@ -896,6 +908,15 @@ public function test_publish_hook_enqueues_translations_for_public_submission():
                 : ''
         );
 
+        $shutdownCallback = null;
+        Functions\when('add_action')->alias(
+            function (string $hook, callable $cb) use (&$shutdownCallback): void {
+                if ($hook === 'shutdown') {
+                    $shutdownCallback = $cb;
+                }
+            }
+        );
+
         $enqueueCall = null;
         Functions\when('cdcf_enqueue_translations_for_submission')->alias(
             function (int $en_id, string $type) use (&$enqueueCall): void {
@@ -906,6 +927,20 @@ function (int $en_id, string $type) use (&$enqueueCall): void {
 
         cdcf_enqueue_translations_on_publish('publish', 'draft', $this->fakePost());
 
+        // Synchronously: NOT called.
+        $this->assertNull(
+            $enqueueCall,
+            'cdcf_enqueue_translations_for_submission must NOT be invoked synchronously inside transition_post_status — it must be deferred to the `shutdown` action so Polylang\'s save_post chain settles first.'
+        );
+
+        // A shutdown callback was registered.
+        $this->assertNotNull(
+            $shutdownCallback,
+            'cdcf_enqueue_translations_on_publish must call add_action(\'shutdown\', $callback) to defer the enqueue out of the post-save chain.'
+        );
+
+        // Driving the deferred callback fires the enqueue with the source post's args.
+        $shutdownCallback();
         $this->assertSame([100, 'project'], $enqueueCall);
     }