diff -r 48c4eec2b7e6 -r 8c2e4d02f4ef wp/wp-admin/js/post.js
--- a/wp/wp-admin/js/post.js	Fri Sep 05 18:40:08 2025 +0200
+++ b/wp/wp-admin/js/post.js	Fri Sep 05 18:52:52 2025 +0200
@@ -343,9 +343,9 @@
 		}
 	}).filter(':visible').find('.wp-tab-first').trigger( 'focus' );
 
-	// Set the heartbeat interval to 15 seconds if post lock dialogs are enabled.
+	// Set the heartbeat interval to 10 seconds if post lock dialogs are enabled.
 	if ( wp.heartbeat && $('#post-lock-dialog').length ) {
-		wp.heartbeat.interval( 15 );
+		wp.heartbeat.interval( 10 );
 	}
 
 	// The form is being submitted by the user.
@@ -434,25 +434,6 @@
 		$previewField.val('');
 	});
 
-	// This code is meant to allow tabbing from Title to Post content.
-	$('#title').on( 'keydown.editor-focus', function( event ) {
-		var editor;
-
-		if ( event.keyCode === 9 && ! event.ctrlKey && ! event.altKey && ! event.shiftKey ) {
-			editor = typeof tinymce != 'undefined' && tinymce.get('content');
-
-			if ( editor && ! editor.isHidden() ) {
-				editor.focus();
-			} else if ( $textarea.length ) {
-				$textarea.trigger( 'focus' );
-			} else {
-				return;
-			}
-
-			event.preventDefault();
-		}
-	});
-
 	// Auto save new posts after a title is typed.
 	if ( $( '#auto_draft' ).val() ) {
 		$( '#title' ).on( 'blur', function() {
@@ -678,8 +659,10 @@
 			'li.popular-category > label input[type="checkbox"]',
 			function() {
 				var t = $(this), c = t.is(':checked'), id = t.val();
-				if ( id && t.parents('#taxonomy-'+taxonomy).length )
-					$('#in-' + taxonomy + '-' + id + ', #in-popular-' + taxonomy + '-' + id).prop( 'checked', c );
+				if ( id && t.parents('#taxonomy-'+taxonomy).length ) {
+					$('input#in-' + taxonomy + '-' + id + ', input[id^="in-' + taxonomy + '-' + id + '-"]').prop('checked', c);
+					$('input#in-popular-' + taxonomy + '-' + id).prop('checked', c);
+				}
 			}
 		);