diff --git a/src/Integrations/Divi/Pages/DiviUpdateAbility.php b/src/Integrations/Divi/Pages/DiviUpdateAbility.php
index 7c35263..03935e6 100644
--- a/src/Integrations/Divi/Pages/DiviUpdateAbility.php
+++ b/src/Integrations/Divi/Pages/DiviUpdateAbility.php
@@ -7,7 +7,10 @@ namespace LIT\MCP\Integrations\Divi\Pages;
 use LIT\MCP\Abilities\Annotations;
 use LIT\MCP\Abilities\Errors;
 use LIT\MCP\Integrations\Divi\BlockTree\Block;
+use LIT\MCP\Integrations\Divi\BlockTree\NodeIndex;
 use LIT\MCP\Integrations\Divi\Compose\ColumnWidths;
+use LIT\MCP\Integrations\Divi\Compose\Composer;
+use LIT\MCP\Integrations\Divi\Compose\LoopScope;
 use LIT\MCP\Integrations\Divi\Design\PresetAssignment;
 use LIT\MCP\Integrations\Divi\Release\DiviFeature;
 use WP_Error;
@@ -21,6 +24,9 @@ defined('ABSPATH') || exit;
  * come back together; only then are the attributes Composer::update() computed set. A node may
  * appear once per call (ruling S14); set and attrs of one change must not reach the same path
  * (ruling S38, checked by Composer::update()).
+ *
+ * Loop content (ruling X3): each change is checked in the loop scope of its node – the stored ancestors plus the
+ * loop attrs this call gives the node or an ancestor – with one Composer per scope.
  */
 final class DiviUpdateAbility extends DiviWriteAbility
 {
@@ -123,14 +129,13 @@ final class DiviUpdateAbility extends DiviWriteAbility
             ]);
         }
 
-        $composer = $composition->composer();
         $errors = [];
         /** @var list<string> $invalidPaths */
         $invalidPaths = [];
         /** @var array<string, int> $seen id => position of its first change */
         $seen = [];
-        /** @var list<array{0: Block, 1: array<string, mixed>, 2: string}> $updates */
-        $updates = [];
+        /** @var list<array{0: Block, 1: array<array-key, mixed>, 2: string}> $pending */
+        $pending = [];
         foreach ($changes as $position => $change) {
             $field = sprintf('changes[%d]', $position);
             if (! is_array($change)) {
@@ -159,10 +164,15 @@ final class DiviUpdateAbility extends DiviWriteAbility
                 continue;
             }
 
-            $result = $composer->update($block, $change, $field);
+            $pending[] = [$block, $change, $field];
+        }
+
+        /** @var list<array{0: Block, 1: array<string, mixed>, 2: string}> $updates */
+        $updates = [];
+        foreach (self::composeInLoops($page->index, $composition, $pending) as $position => $result) {
             $errors += $result['errors'];
             array_push($invalidPaths, ...$result['invalid_paths']);
-            $updates[] = [$block, $result['attrs'], $field];
+            $updates[] = [$pending[$position][0], $result['attrs'], $pending[$position][2]];
         }
 
         if ($errors === []) {
@@ -189,4 +199,46 @@ final class DiviUpdateAbility extends DiviWriteAbility
 
         return $change;
     }
+
+    /**
+     * Composer::update() of every pending change in its loop scope (ruling X3). First with the stored ancestors;
+     * then changes whose scope the new attrs of this call move (a loop switched on, off or to another kind on the
+     * node or an ancestor) are composed again in that scope – loop attrs are no client content, so the second
+     * pass sees the same loops.
+     *
+     * @param list<array{0: Block, 1: array<array-key, mixed>, 2: string}> $pending
+     * @return list<array{attrs: array<string, mixed>, errors: array<string, string>, invalid_paths: list<string>}>
+     */
+    private static function composeInLoops(NodeIndex $index, DiviComposition $composition, array $pending): array
+    {
+        /** @var array<string, Composer> $composers query type ('' = no loop) => Composer of that scope */
+        $composers = [];
+        $scopes = [];
+        $results = [];
+        foreach ($pending as $position => [$block, $change, $field]) {
+            $scopes[$position] = self::loopAt($index, $block);
+            $results[$position] = self::composerFor($composition, $scopes[$position], $composers)
+                ->update($block, $change, $field);
+        }
+
+        $newAttrs = [];
+        foreach ($pending as $position => [$block]) {
+            $newAttrs[(string) $index->idOf($block)] = $results[$position]['attrs'];
+        }
+        foreach ($pending as $position => [$block, $change, $field]) {
+            $scope = self::loopAt($index, $block, $newAttrs);
+            if ($scope->queryType() !== $scopes[$position]->queryType()) {
+                $results[$position] = self::composerFor($composition, $scope, $composers)
+                    ->update($block, $change, $field);
+            }
+        }
+
+        return $results;
+    }
+
+    /** @param array<string, Composer> $composers One Composer per loop scope (S31 as reworded by X3). */
+    private static function composerFor(DiviComposition $composition, LoopScope $scope, array &$composers): Composer
+    {
+        return $composers[$scope->queryType() ?? ''] ??= $composition->inLoop($scope)->composer();
+    }
 }
diff --git a/tests/Unit/Integrations/Divi/Pages/DiviLoopWriteTest.php b/tests/Unit/Integrations/Divi/Pages/DiviLoopWriteTest.php
index f28f89b..beb92a2 100644
--- a/tests/Unit/Integrations/Divi/Pages/DiviLoopWriteTest.php
+++ b/tests/Unit/Integrations/Divi/Pages/DiviLoopWriteTest.php
@@ -172,4 +172,53 @@ final class DiviLoopWriteTest extends DiviWriteAbilityTestCase
         ]]);
         self::assertTrue($withoutLoopContent['ok'], (string) json_encode($withoutLoopContent));
     }
+
+    /** Ruling X3: one Composer per loop scope – changes in a post loop and a term loop in one call. */
+    public function testUpdateChecksEveryChangeInItsOwnLoop(): void
+    {
+        $result = $this->changeAll([
+            ['id' => 's0.r0.c0.m1', 'set' => ['content' => '{{loop:post_date}}']],
+            ['id' => 's0.r0.c1.m0', 'set' => ['content' => '{{loop:term_name}}']],
+            ['id' => 's0.r0.c2.m0', 'set' => ['content' => '<p>Neu</p>']],
+        ]);
+
+        self::assertTrue($result['ok'], (string) json_encode($result));
+        self::assertStringContainsString('loop_term_name', $this->saved[0]);
+
+        $refused = $this->changeAll([
+            ['id' => 's0.r0.c0.m1', 'set' => ['content' => '{{loop:term_name}}']],
+            ['id' => 's0.r0.c2.m0', 'set' => ['content' => '{{loop:post_date}}']],
+        ]);
+        $problems = self::errorFields($refused);
+        self::assertStringContainsString('Typ: Beiträge', $problems['changes[0].set.content'] ?? '');
+        self::assertStringContainsString('braucht eine Divi-Schleife', $problems['changes[1].set.content'] ?? '');
+    }
+
+    /**
+     * Ruling X3: the scope of a change takes the loop attrs this call gives the node or an ancestor – a loop
+     * switched on admits its content, a loop switched to another kind refuses the old kind's content.
+     */
+    public function testUpdateUsesTheLoopsThisCallSets(): void
+    {
+        $switchedOn = $this->changeAll([
+            ['id' => 's0.r0.c2', 'attrs' => ['module.advanced.loop' => ['desktop' => self::TERM_LOOP]]],
+            ['id' => 's0.r0.c2.m0', 'set' => ['content' => '{{loop:term_name}}']],
+        ]);
+        self::assertTrue($switchedOn['ok'], (string) json_encode($switchedOn));
+
+        $own = $this->changeAll([[
+            'id' => 's0.r0.c0.m1',
+            'attrs' => ['module.advanced.loop' => ['desktop' => self::TERM_LOOP]],
+            'set' => ['content' => '{{loop:term_name}}'],
+        ]]);
+        self::assertTrue($own['ok'], (string) json_encode($own));
+
+        $switchedKind = $this->changeAll([
+            ['id' => 's0.r0.c0', 'attrs' => ['module.advanced.loop' => ['desktop' => self::TERM_LOOP]]],
+            ['id' => 's0.r0.c0.m0', 'set' => ['content' => '{{loop:post_date}}']],
+        ]);
+        $problems = self::errorFields($switchedKind);
+        self::assertStringContainsString('Typ: Terme', $problems['changes[1].set.content'] ?? '');
+        self::assertCount(2, $this->saved);
+    }
 }