diff --git a/php-transformer/src/HtmlToBlocks/Style/StyleAttributeMapper.php b/php-transformer/src/HtmlToBlocks/Style/StyleAttributeMapper.php
index d812d0d1..ace96b4f 100644
--- a/php-transformer/src/HtmlToBlocks/Style/StyleAttributeMapper.php
+++ b/php-transformer/src/HtmlToBlocks/Style/StyleAttributeMapper.php
@@ -188,9 +188,9 @@ public function serialize(array $style): array
         if ( '' !== trim((string) ($dimensions['minHeight'] ?? '')) ) {
             $declarations[] = 'min-height:' . trim((string) $dimensions['minHeight']);
         }
-        if ( '' !== trim((string) ($dimensions['maxWidth'] ?? '')) ) {
-            $declarations[] = 'max-width:' . trim((string) $dimensions['maxWidth']);
-        }
+        // Core stores dimensions.maxWidth in block attrs but does not reproduce
+        // it as an inline wrapper declaration in save(), so emitting it here
+        // makes otherwise native blocks fail editor validation.
 
         $typography    = is_array($style['typography'] ?? null) ? $style['typography'] : array();
         $typographyMap = array(
diff --git a/php-transformer/tests/unit/block-style-support-conversion.php b/php-transformer/tests/unit/block-style-support-conversion.php
index 2c4a15e8..a90c1ff6 100644
--- a/php-transformer/tests/unit/block-style-support-conversion.php
+++ b/php-transformer/tests/unit/block-style-support-conversion.php
@@ -66,8 +66,8 @@
 
 $assert('1120px' === ($cardShellAttrs['style']['dimensions']['maxWidth'] ?? ''), '17: section max-width maps to dimensions support', json_encode($cardShellAttrs['style']['dimensions'] ?? array()));
 $assert('360px' === ($cardAttrs['style']['dimensions']['maxWidth'] ?? ''), '18: card max-width maps to dimensions support', json_encode($cardAttrs['style']['dimensions'] ?? array()));
-$assert(str_contains($cardMarkup, 'max-width:1120px'), '19: rendered section preserves max-width geometry', $cardMarkup);
-$assert(str_contains($cardMarkup, 'max-width:360px'), '20: rendered card preserves max-width geometry', $cardMarkup);
+$assert(! str_contains($cardMarkup, 'max-width:1120px'), '19: rendered section omits max-width that core save() does not reproduce', $cardMarkup);
+$assert(! str_contains($cardMarkup, 'max-width:360px'), '20: rendered card omits max-width that core save() does not reproduce', $cardMarkup);
 $assert(! str_contains($cardMarkup, 'style="max-width:1120px;margin:0 auto;padding:5rem 2rem"'), '21: rendered section does not keep unsupported raw style wholesale', $cardMarkup);
 
 $labelHtml = '<section class="pricing"><div class="section-head"><div class="tag">Pricing</div><h2>Simple plans</h2></div><article class="pricing-card"><div class="tier-name">Team</div><div class="tier-price"><span class="amount">$29</span>/mo</div><div class="use-case-result">Launch faster</div></article></section>';