Index: src/wp-admin/edit-form-blocks.php
===================================================================
--- src/wp-admin/edit-form-blocks.php	(revision 50691)
+++ src/wp-admin/edit-form-blocks.php	(working copy)
@@ -346,7 +346,7 @@
 	'enableCustomSpacing'                  => $custom_spacing,
 );
 
-$autosave = wp_get_post_autosave( $post_ID );
+$autosave = wp_get_post_autosave( $post->ID );
 if ( $autosave ) {
 	if ( mysql2date( 'U', $autosave->post_modified_gmt, false ) > mysql2date( 'U', $post->post_modified_gmt, false ) ) {
 		$editor_settings['autosave'] = array(