do changes

Closes #3525234

src/Plugin/CustomElementsFieldFormatter/CoreFieldCeFieldFormatter.php

@@ -3,6 +3,7 @@
 namespace Drupal\custom_elements\Plugin\CustomElementsFieldFormatter;
 
 use Drupal\Component\Plugin\Factory\DefaultFactory;
+use Drupal\Component\Utility\DeprecationHelper;
 use Drupal\Core\Cache\CacheableDependencyInterface;
 use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Extension\ModuleHandlerInterface;
@@ -146,7 +147,14 @@ class CoreFieldCeFieldFormatter extends CustomElementsFieldFormatterBase {
     }
     else {
       // Render into markup and set the string value as attribute.
-      $markup = $this->renderer->renderPlain($elements);
+      /** @var \Drupal\Core\Render\RendererInterface $renderer */
+      $renderer = $this->renderer;
+      $markup = DeprecationHelper::backwardsCompatibleCall(
+        currentVersion: \Drupal::VERSION,
+        deprecatedVersion: '10.3',
+        currentCallable: fn() => $renderer->renderInIsolation($elements),
+        deprecatedCallable: fn() => $renderer->renderPlain($elements),
+      );
       $custom_element->setAttribute($this->getName(), (string) $markup);
       $custom_element->addCacheableDependency(CacheableMetadata::createFromRenderArray($elements));
     }