diff --git a/src/dialogs/make-dialog-manager.ts b/src/dialogs/make-dialog-manager.ts
index 3d90a421f6..9cfb685ad0 100644
--- a/src/dialogs/make-dialog-manager.ts
+++ b/src/dialogs/make-dialog-manager.ts
@@ -62,7 +62,7 @@ export const showDialog = async (
   dialogParams: unknown,
   dialogImport?: () => Promise<unknown>,
   addHistory = true
-) => {
+): Promise<boolean> => {
   if (!(dialogTag in LOADED)) {
     if (!dialogImport) {
       if (__DEV__) {
@@ -71,7 +71,7 @@ export const showDialog = async (
           "Asked to show dialog that's not loaded and can't be imported"
         );
       }
-      return;
+      return false;
     }
     LOADED[dialogTag] = {
       element: dialogImport().then(() => {
@@ -128,6 +128,8 @@ export const showDialog = async (
   // so it's guaranteed to be on top of the other elements
   root.appendChild(dialogElement);
   dialogElement.showDialog(dialogParams);
+
+  return true;
 };
 
 export const replaceDialog = (dialogElement: HassDialog) => {
diff --git a/src/external_app/external_app_entrypoint.ts b/src/external_app/external_app_entrypoint.ts
index e39ca5b566..39176b652b 100644
--- a/src/external_app/external_app_entrypoint.ts
+++ b/src/external_app/external_app_entrypoint.ts
@@ -6,6 +6,7 @@ This is the entry point for providing external app stuff from app entrypoint.
 */
 
 import { fireEvent } from "../common/dom/fire_event";
+import { mainWindow } from "../common/dom/get_main_window";
 import { HomeAssistantMain } from "../layouts/home-assistant-main";
 import type { EMIncomingMessageCommands } from "./external_messaging";
 
@@ -45,6 +46,15 @@ const handleExternalMessage = (
       result: null,
     });
   } else if (msg.command === "sidebar/toggle") {
+    if (mainWindow.history.state?.open) {
+      bus.fireMessage({
+        id: msg.id,
+        type: "result",
+        success: false,
+        error: { code: "not_allowed", message: "dialog open" },
+      });
+      return true;
+    }
     fireEvent(hassMainEl, "hass-toggle-menu");
     bus.fireMessage({
       id: msg.id,
@@ -53,6 +63,15 @@ const handleExternalMessage = (
       result: null,
     });
   } else if (msg.command === "sidebar/show") {
+    if (mainWindow.history.state?.open) {
+      bus.fireMessage({
+        id: msg.id,
+        type: "result",
+        success: false,
+        error: { code: "not_allowed", message: "dialog open" },
+      });
+      return true;
+    }
     fireEvent(hassMainEl, "hass-toggle-menu", { open: true });
     bus.fireMessage({
       id: msg.id,
diff --git a/src/state/url-sync-mixin.ts b/src/state/url-sync-mixin.ts
index d8cc554b75..387bf8fd9b 100644
--- a/src/state/url-sync-mixin.ts
+++ b/src/state/url-sync-mixin.ts
@@ -1,5 +1,5 @@
 /* eslint-disable no-console */
-import { ReactiveElement } from "lit";
+import { PropertyValueMap, ReactiveElement } from "lit";
 import { HASSDomEvent } from "../common/dom/fire_event";
 import { mainWindow } from "../common/dom/get_main_window";
 import {
@@ -31,8 +31,11 @@ export const urlSyncMixin = <
 
         public connectedCallback(): void {
           super.connectedCallback();
-          if (history.length === 1) {
-            history.replaceState({ ...history.state, root: true }, "");
+          if (mainWindow.history.length === 1) {
+            mainWindow.history.replaceState(
+              { ...mainWindow.history.state, root: true },
+              ""
+            );
           }
           mainWindow.addEventListener("popstate", this._popstateChangeListener);
           this.addEventListener("dialog-closed", this._dialogClosedListener);
@@ -47,6 +50,15 @@ export const urlSyncMixin = <
           this.removeEventListener("dialog-closed", this._dialogClosedListener);
         }
 
+        protected firstUpdated(
+          changedProperties: PropertyValueMap<any> | Map<PropertyKey, unknown>
+        ): void {
+          super.firstUpdated(changedProperties);
+          if (mainWindow.history.state?.dialog) {
+            this._handleDialogStateChange(mainWindow.history.state);
+          }
+        }
+
         private _dialogClosedListener = (
           ev: HASSDomEvent<DialogClosedParams>
         ) => {
@@ -67,7 +79,7 @@ export const urlSyncMixin = <
             if (DEBUG) {
               console.log("remove state", ev.detail.dialog);
             }
-            if (history.length) {
+            if (mainWindow.history.length) {
               this._ignoreNextPopState = true;
               historyPromise = new Promise((resolve) => {
                 historyResolve = () => {
@@ -145,13 +157,21 @@ export const urlSyncMixin = <
             }
             return;
           }
-          if (state.dialogParams !== null) {
-            showDialog(
+          let shown = false;
+          if (state.open && state.dialogParams !== null) {
+            shown = await showDialog(
               this,
               this.shadowRoot!,
               state.dialog,
               state.dialogParams
             );
           }
+          if (!shown) {
+            // can't open dialog, update state
+            mainWindow.history.replaceState(
+              { ...mainWindow.history.state, open: false },
+              ""
+            );
+          }
         }
       };