Template columns ignored in editor

I am using columns in my default page template. In the left column is the post featured image and in the right column is the post content.

When I edit the template with the editor, everything works fine. But when I edit a page, the two columns are not displayed. Only the content of the post is visible – without padding left or right. In the frontend, it works again and the content is displayed correctly as specified by the template.

Template (page.html)

<!-- wp:template-part {"slug":"header","tagName":"header"} /-->

<!-- wp:group {"tagName":"main","style":{"spacing":{"margin":{"top":"var:preset|spacing|50"}}},"layout":{"type":"constrained"}} -->
<main class="wp-block-group" style="margin-top:var(--wp--preset--spacing--50)">
	<!-- wp:columns {"align":"wide","style":{"spacing":{"blockGap":{"left":"var:preset|spacing|50"}}}} -->
	<div class="wp-block-columns alignwide">
		<!-- wp:column {"width":"25%","style":{"border":{"top":{"color":"var:preset|color|orange","width":"1px"},"right":[],"bottom":[],"left":[]}}} -->
		<div class="wp-block-column" style="border-top-color:var(--wp--preset--color--orange);border-top-width:1px;flex-basis:25%">
			<!-- wp:post-featured-image {"aspectRatio":"1"} /-->
		</div>
		<!-- /wp:column -->
		<!-- wp:column {"width":"75%"} -->
		<div class="wp-block-column" style="flex-basis:75%">
			<!-- wp:post-title {"level":1} /-->
			<!-- wp:post-content {"layout":{"type":"default"}} /-->
		</div>
		<!-- /wp:column -->
	</div>
	<!-- /wp:columns -->
</main>
<!-- /wp:group -->

<!-- wp:template-part {"slug":"footer","tagName":"footer"} /-->