diff -r 7b1b88e27a20 -r 48c4eec2b7e6 wp/wp-includes/widgets/class-wp-widget-block.php
--- a/wp/wp-includes/widgets/class-wp-widget-block.php	Thu Sep 29 08:06:27 2022 +0200
+++ b/wp/wp-includes/widgets/class-wp-widget-block.php	Fri Sep 05 18:40:08 2025 +0200
@@ -223,7 +223,7 @@
 	 * @return bool Updated `is_wide` value.
 	 */
 	public function set_is_wide_widget_in_customizer( $is_wide, $widget_id ) {
-		if ( strpos( $widget_id, 'block-' ) === 0 ) {
+		if ( str_starts_with( $widget_id, 'block-' ) ) {
 			return false;
 		}