diff --git a/.gitignore b/.gitignore
index d2694b1a..bf979cac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 .idea/
 .phpunit.result.cache
 css/*.min.css
+js/*.min.js
 vendor/
 node_modules/
 composer.lock
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b36210c..ca39bf2e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,10 +5,11 @@ All notable changes to this project will be documented in this file. This projec
 
 Requires PHP 5.6 and WordPress 4.7 or above
 
+* Fix: invalidate cache when permalink changes (#285, #286, props raffaelj)
 * Enhance: adjust styling for setup instructions (#215, props timse201)
 * Enhance: update hooks for Multisite initialization in WordPress 5.1 and above (#246, props ouun)
 * Enhance: rework flush hooks and add some third-party triggers for Autoptimize and WooCommerce (#225, props timse201)
-
+* Fix: correctly add user-agent to robots.txt (#282) (#283)
 
 ## 2.3.2
 * Fix: enforce WordPress environment for caching modules (#221, props timse201)
diff --git a/css/dashboard.css b/css/dashboard.css
index 6b790189..aad8035a 100644
--- a/css/dashboard.css
+++ b/css/dashboard.css
@@ -5,6 +5,10 @@
 	fill: #606a73;
 }
 
+html.dark-mode body:not(.block-editor-page) #dashboard_right_now .cachify-icon {
+	fill: #bbc8d4;
+}
+
 #dashboard_right_now li a.cachify-glance::before {
 	content: "";
 	padding: 0;
diff --git a/inc/class-cachify.php b/inc/class-cachify.php
index 9166a60d..ba5fc792 100644
--- a/inc/class-cachify.php
+++ b/inc/class-cachify.php
@@ -93,7 +93,7 @@ public function __construct() {
 
 		/* Flush Hooks */
 		add_action( 'init', array( __CLASS__, 'register_flush_cache_hooks' ), 10, 0 );
-		add_action( 'save_post', array( __CLASS__, 'save_update_trash_post' ) );
+		add_action( 'post_updated', array( __CLASS__, 'save_update_trash_post' ), 10, 3 );
 		add_action( 'pre_post_update', array( __CLASS__, 'post_update' ), 10, 2 );
 		add_action( 'cachify_remove_post_cache', array( __CLASS__, 'remove_page_cache_by_post_id' ) );
 		add_action( 'comment_post', array( __CLASS__, 'new_comment' ), 99, 2 );
@@ -156,8 +156,6 @@ public function __construct() {
 
 			add_action( 'admin_enqueue_scripts', array( __CLASS__, 'admin_dashboard_styles' ) );
 
-			add_action( 'doing_dark_mode', array( __CLASS__, 'admin_dashboard_dark_mode_styles' ) );
-
 			add_filter( 'dashboard_glance_items', array( __CLASS__, 'add_dashboard_count' ) );
 
 			add_filter( 'plugin_row_meta', array( __CLASS__, 'row_meta' ), 10, 2 );
@@ -167,7 +165,7 @@ public function __construct() {
 		} else {
 			/* Frontend */
 			add_action( 'template_redirect', array( __CLASS__, 'manage_cache' ), 0 );
-			add_action( 'do_robots', array( __CLASS__, 'robots_txt' ) );
+			add_filter( 'robots_txt', array( __CLASS__, 'robots_txt' ) );
 		}
 	}
 
@@ -435,15 +433,18 @@ private static function _get_options() {
 	/**
 	 * Modify robots.txt
 	 *
+	 * @param string $output The robots.txt output.
+	 *
 	 * @since 1.0
 	 * @since 2.1.9
-	 * @since 2.4.0 Removed $data parameter and return value.
 	 */
-	public static function robots_txt() {
+	public static function robots_txt( $output ) {
 		/* HDD only */
 		if ( self::METHOD_HDD === self::$options['use_apc'] ) {
-			echo 'Disallow: */cache/cachify/';
+			$output .= "\nUser-agent: *\nDisallow: */cache/cachify/\n";
 		}
+
+		return $output;
 	}
 
 	/**
@@ -1047,14 +1048,16 @@ public static function publish_post_types( $post_id, $post ) {
 	/**
 	 * Removes the post type cache if saved or updated
 	 *
-	 * @param int $id Post ID.
+	 * @param int     $id          Post ID.
+	 * @param WP_Post $post_after  Post object following the update.
+	 * @param WP_Post $post_before Post object before the update.
 	 *
 	 * @since 2.0.3
 	 * @since 2.1.7 Make the function public.
-	 * @since 2.4.0 Renamed to save_update_trash_post with $id parameter.
+	 * @since 2.4.0 Renamed to save_update_trash_post and introduced parameters.
 	 */
-	public static function save_update_trash_post( $id ) {
-		$status = get_post_status( $id );
+	public static function save_update_trash_post( $id, $post_after, $post_before ) {
+		$status = get_post_status( $post_before );
 
 		/* Post type published? */
 		if ( 'publish' === $status ) {
@@ -1644,6 +1647,8 @@ public static function admin_dashboard_styles() {
 	 * Fixing some admin dashboard styles
 	 *
 	 * @since 2.3.0
+	 *
+	 * @deprecated included in dashboard.css since 2.4
 	 */
 	public static function admin_dashboard_dark_mode_styles() {
 		wp_add_inline_style( 'cachify-dashboard', '#dashboard_right_now .cachify-icon use { fill: #bbc8d4; }' );
diff --git a/js/admin-bar-flush.min.js b/js/admin-bar-flush.min.js
deleted file mode 100644
index 16d25798..00000000
--- a/js/admin-bar-flush.min.js
+++ /dev/null
@@ -1,6 +0,0 @@
-(function(){var is_flushing=!1,admin_bar_cachify_list_item=document.getElementById('wp-admin-bar-cachify'),flush_link=admin_bar_cachify_list_item.querySelector('a.ab-item'),fallback_url=flush_link.getAttribute('href'),aria_live_area=document.querySelector('.ab-aria-live-area');var button=document.createRange().createContextualFragment('<button class="ab-item">'+flush_link.innerHTML+'</button>');flush_link.parentNode.replaceChild(button,flush_link);var admin_bar_icon=admin_bar_cachify_list_item.querySelector('#wp-admin-bar-cachify .ab-icon');document.querySelector('#wp-admin-bar-cachify .ab-item').addEventListener('click',flush);admin_bar_icon.addEventListener('animationend',function(){admin_bar_icon.classList.remove('animate-fade')});function flush_icon_remove_classes(){var classes=['animate-fade','animate-pulse','dashicons-trash','dashicons-yes','dashicons-yes-alt','dashicons-dismiss',];for(var i=0;i<classes.length;i++){admin_bar_icon.classList.remove(classes[i])}}
-function start_flush_icon_reset_timeout(){setTimeout(function(){flush_icon_remove_classes();admin_bar_icon.classList.add('animate-fade');admin_bar_icon.classList.add('dashicons-trash');is_flushing=!1;aria_live_area.textContent=''},2000)}
-function flush(event){event.preventDefault();if(is_flushing){return}
-is_flushing=!0;aria_live_area.textContent=cachify_admin_bar_flush_ajax_object.flushing;if(admin_bar_icon!==null){flush_icon_remove_classes();admin_bar_icon.classList.add('animate-pulse');admin_bar_icon.classList.add('dashicons-trash')}
-var request=new XMLHttpRequest();request.addEventListener('load',function(){if(this.status===200){start_flush_icon_reset_timeout();flush_icon_remove_classes();admin_bar_icon.classList.add('animate-fade');admin_bar_icon.classList.add(cachify_admin_bar_flush_ajax_object.dashicon_success);aria_live_area.textContent=cachify_admin_bar_flush_ajax_object.flushed;return}
-window.location=fallback_url});request.addEventListener('error',function(){window.location=fallback_url});request.open('DELETE',cachify_admin_bar_flush_ajax_object.url);request.setRequestHeader('X-WP-Nonce',cachify_admin_bar_flush_ajax_object.nonce);request.send()}}())
\ No newline at end of file
diff --git a/tests/test-cachify.php b/tests/test-cachify.php
index f32225eb..052ccf6b 100644
--- a/tests/test-cachify.php
+++ b/tests/test-cachify.php
@@ -104,4 +104,33 @@ public function test_on_activation() {
 		Cachify::on_activation();
 		self::assertEquals( array() , get_option( 'cachify' ), 'Cachify option not initialized' );
 	}
+
+
+	/**
+	 * Test hook for robots.txt customization.
+	 */
+	public function test_robots_txt() {
+		// Initial robots.txt content.
+		$robots_txt = "User-agent: *\nDisallow: /wordpress/wp-admin/\nAllow: /wordpress/wp-admin/admin-ajax.php\n";
+
+		// DB cache enabled.
+		update_option( 'cachify' , array( 'use_apc' => Cachify::METHOD_DB ) );
+		new Cachify();
+
+		self::assertEquals(
+			$robots_txt,
+			Cachify::robots_txt( $robots_txt ),
+			'robots.tst should not be modified using DB cache'
+		);
+
+		// HDD cache enabled.
+		update_option( 'cachify' , array( 'use_apc' => Cachify::METHOD_HDD ) );
+		new Cachify();
+
+		self::assertEquals(
+			$robots_txt . "\nUser-agent: *\nDisallow: */cache/cachify/\n",
+			Cachify::robots_txt( $robots_txt ),
+			'robots.tst should have been modified using HDD cache'
+		);
+	}
 }