diff --git a/dist/better-xcloud.lite.user.js b/dist/better-xcloud.lite.user.js
index 40b4e8d..22aab77 100644
--- a/dist/better-xcloud.lite.user.js
+++ b/dist/better-xcloud.lite.user.js
@@ -1,7 +1,7 @@
 // ==UserScript==
 // @name         Better xCloud (Lite)
 // @namespace    https://github.com/redphx
-// @version      5.9.4
+// @version      5.9.5-beta
 // @description  Improve Xbox Cloud Gaming (xCloud) experience
 // @author       redphx
 // @license      MIT
@@ -105,7 +105,7 @@ class UserAgent {
   });
  }
 }
-var SCRIPT_VERSION = "5.9.4", SCRIPT_VARIANT = "lite", AppInterface = window.AppInterface;
+var SCRIPT_VERSION = "5.9.5-beta", SCRIPT_VARIANT = "lite", AppInterface = window.AppInterface;
 UserAgent.init();
 var userAgent = window.navigator.userAgent.toLowerCase(), isTv = userAgent.includes("smart-tv") || userAgent.includes("smarttv") || /\baft.*\b/.test(userAgent), isVr = window.navigator.userAgent.includes("VR") && window.navigator.userAgent.includes("OculusBrowser"), browserHasTouchSupport = "ontouchstart" in window || navigator.maxTouchPoints > 0, userAgentHasTouchSupport = !isTv && !isVr && browserHasTouchSupport, supportMkb = AppInterface || !userAgent.match(/(android|iphone|ipad)/), STATES = {
  supportedRegion: !0,
@@ -4895,6 +4895,8 @@ class GuideMenu {
  }
  observe($addedElm) {
   let className = $addedElm.className;
+  if (!className) className = $addedElm.firstElementChild?.className ?? "";
+  if (!className || className.startsWith("bx-")) return;
   if (!className.startsWith("NavigationAnimation") && !className.startsWith("DialogRoutes") && !className.startsWith("Dialog-module__container")) return;
   let $selectedTab = $addedElm.querySelector("div[class^=NavigationMenu] button[aria-selected=true");
   if ($selectedTab) {
@@ -5956,7 +5958,7 @@ class RootDialogObserver {
     if (mutation.type !== "childList") continue;
     if (BX_FLAGS.Debug && BxLogger.warning("RootDialog", "added", mutation.addedNodes), mutation.addedNodes.length === 1) {
      let $addedElm = mutation.addedNodes[0];
-     if ($addedElm instanceof HTMLElement && $addedElm.className) RootDialogObserver.handleAddedElement($root, $addedElm);
+     if ($addedElm instanceof HTMLElement) RootDialogObserver.handleAddedElement($root, $addedElm);
     }
     let shown = !!($root.firstElementChild && $root.firstElementChild.childElementCount > 0);
     if (shown !== beingShown) beingShown = shown, BxEvent.dispatch(window, shown ? BxEvent.XCLOUD_DIALOG_SHOWN : BxEvent.XCLOUD_DIALOG_DISMISSED);
diff --git a/dist/better-xcloud.user.js b/dist/better-xcloud.user.js
index 2734b40..aa701f9 100644
--- a/dist/better-xcloud.user.js
+++ b/dist/better-xcloud.user.js
@@ -1,7 +1,7 @@
 // ==UserScript==
 // @name         Better xCloud
 // @namespace    https://github.com/redphx
-// @version      5.9.4
+// @version      5.9.5-beta
 // @description  Improve Xbox Cloud Gaming (xCloud) experience
 // @author       redphx
 // @license      MIT
@@ -107,7 +107,7 @@ class UserAgent {
   });
  }
 }
-var SCRIPT_VERSION = "5.9.4", SCRIPT_VARIANT = "full", AppInterface = window.AppInterface;
+var SCRIPT_VERSION = "5.9.5-beta", SCRIPT_VARIANT = "full", AppInterface = window.AppInterface;
 UserAgent.init();
 var userAgent = window.navigator.userAgent.toLowerCase(), isTv = userAgent.includes("smart-tv") || userAgent.includes("smarttv") || /\baft.*\b/.test(userAgent), isVr = window.navigator.userAgent.includes("VR") && window.navigator.userAgent.includes("OculusBrowser"), browserHasTouchSupport = "ontouchstart" in window || navigator.maxTouchPoints > 0, userAgentHasTouchSupport = !isTv && !isVr && browserHasTouchSupport, supportMkb = AppInterface || !userAgent.match(/(android|iphone|ipad)/), STATES = {
  supportedRegion: !0,
@@ -6514,6 +6514,8 @@ class GuideMenu {
  }
  observe($addedElm) {
   let className = $addedElm.className;
+  if (!className) className = $addedElm.firstElementChild?.className ?? "";
+  if (!className || className.startsWith("bx-")) return;
   if (className.includes("AchievementsButton-module__progressBarContainer")) {
    TrueAchievements.getInstance().injectAchievementsProgress($addedElm);
    return;
@@ -7924,7 +7926,7 @@ class RootDialogObserver {
     if (mutation.type !== "childList") continue;
     if (BX_FLAGS.Debug && BxLogger.warning("RootDialog", "added", mutation.addedNodes), mutation.addedNodes.length === 1) {
      let $addedElm = mutation.addedNodes[0];
-     if ($addedElm instanceof HTMLElement && $addedElm.className) RootDialogObserver.handleAddedElement($root, $addedElm);
+     if ($addedElm instanceof HTMLElement) RootDialogObserver.handleAddedElement($root, $addedElm);
     }
     let shown = !!($root.firstElementChild && $root.firstElementChild.childElementCount > 0);
     if (shown !== beingShown) beingShown = shown, BxEvent.dispatch(window, shown ? BxEvent.XCLOUD_DIALOG_SHOWN : BxEvent.XCLOUD_DIALOG_DISMISSED);
diff --git a/src/modules/ui/guide-menu.ts b/src/modules/ui/guide-menu.ts
index 0fbb8d2..b086906 100644
--- a/src/modules/ui/guide-menu.ts
+++ b/src/modules/ui/guide-menu.ts
@@ -178,7 +178,16 @@ export class GuideMenu {
     }
 
     observe($addedElm: HTMLElement) {
-        const className = $addedElm.className;
+        let className = $addedElm.className;
+
+        // Fix custom buttons disappearing in Guide Menu (#551)
+        if (!className) {
+            className = $addedElm.firstElementChild?.className ?? '';
+        }
+
+        if (!className || className.startsWith('bx-')) {
+            return;
+        }
 
         // TrueAchievements
         if (isFullVersion() && className.includes('AchievementsButton-module__progressBarContainer')) {
diff --git a/src/utils/root-dialog-observer.ts b/src/utils/root-dialog-observer.ts
index f66c0c8..3361950 100644
--- a/src/utils/root-dialog-observer.ts
+++ b/src/utils/root-dialog-observer.ts
@@ -79,7 +79,7 @@ export class RootDialogObserver {
                 BX_FLAGS.Debug && BxLogger.warning('RootDialog', 'added', mutation.addedNodes);
                 if (mutation.addedNodes.length === 1) {
                     const $addedElm = mutation.addedNodes[0];
-                    if ($addedElm instanceof HTMLElement && $addedElm.className) {
+                    if ($addedElm instanceof HTMLElement) {
                         RootDialogObserver.handleAddedElement($root, $addedElm);
                     }
                 }