diff --git a/src/base/scripts/electron-tabs.js b/src/base/scripts/electron-tabs.js
index 4d85250..1102b03 100644
--- a/src/base/scripts/electron-tabs.js
+++ b/src/base/scripts/electron-tabs.js
@@ -22,12 +22,21 @@ window.addEventListener("DOMContentLoaded", async () => {
   tabGroup?.on("tab-removed", () => {
     ATWC();
   });
+  tabGroup?.on("tab-added", () => {
+    ATWC();
+  });
 
   prepareTabReloadButton();
 });
 
 window.api.onOpenTab(openTab);
 
+async function resetTabs() {
+  const tabGroup = await getTabGroup();
+  tabGroup?.eachTab((tab) => tab.close(false));
+  openTab();
+}
+
 /**
  * @param {string =} href
  */
@@ -46,10 +55,14 @@ async function setDefaultTab(href) {
 async function openTab(href) {
   const tabGroup = await getTabGroup();
 
-  tabGroup?.addTab({
-    ...DEFAULT_TAB_OPTIONS,
-    ...(href ? { src: href } : {}),
-  });
+  tabGroup?.addTab(
+    href
+      ? {
+          ...DEFAULT_TAB_OPTIONS,
+          src: href,
+        }
+      : undefined
+  );
 }
 
 async function prepareTabReloadButton() {
diff --git a/src/base/scripts/instance.js b/src/base/scripts/instance.js
index 85e006b..73e4622 100644
--- a/src/base/scripts/instance.js
+++ b/src/base/scripts/instance.js
@@ -1,4 +1,8 @@
 const INSTANCE_STORE_KEY = "Instance";
+const INSTANCE_EVENTS = Object.freeze({
+  REGISTER: "registerInstance",
+  REMOVE: "removeInstance",
+});
 
 window.addEventListener("DOMContentLoaded", async () => {
   const savedInstance = await registerSavedInstance();
@@ -24,14 +28,25 @@ async function prepareSaveButton() {
 async function saveInstance(trigger) {
   const isInputButton = trigger instanceof HTMLInputElement;
   const { instanceField } = await getInstanceSettingsForm();
-  
   const instance = instanceField?.value;
+
   if (instance) {
     localStorage.setItem(INSTANCE_STORE_KEY, instance);
+    window.api.send(INSTANCE_EVENTS.REGISTER, instance);
+    await setDefaultTab(instance);
   } else {
+    const savedInstance = localStorage.getItem(INSTANCE_STORE_KEY);
+    
+    if (savedInstance) {
+      window.api.send(INSTANCE_EVENTS.REMOVE, savedInstance);
+    }
+    
     localStorage.removeItem(INSTANCE_STORE_KEY);
+    await setDefaultTab();
   }
-  
+
+  resetTabs();
+
   if (isInputButton) {
     trigger.style.backgroundColor = "#00ff89";
     trigger.setAttribute("value", "Saved!");
@@ -48,8 +63,8 @@ async function registerSavedInstance() {
   if (savedInstance) {
     const { instanceField } = await getInstanceSettingsForm();
 
-    window.api.send("registerInstance", savedInstance);
-    
+    window.api.send(INSTANCE_EVENTS.REGISTER, savedInstance);
+
     if (instanceField) {
       instanceField.value = savedInstance;
     }
diff --git a/src/process/navigation.js b/src/process/navigation.js
index 49fd04b..b682011 100644
--- a/src/process/navigation.js
+++ b/src/process/navigation.js
@@ -15,18 +15,28 @@ const ALLOWED_EXTERNAL_URLS = Object.freeze([
   "https://github.com/penpot/penpot",
 ]);
 
-/** @type {string[]} */
-const userInstances = [];
+/** @type {Set<string>} */
+const userInstances = new Set();
 
 ipcMain.on("registerInstance", (event, instance) => {
   try {
     const url = new URL(instance);
-    userInstances.push(url.origin);
+    userInstances.clear();
+    userInstances.add(url.origin);
   } catch (error) {
     console.error(`[ERROR] [IPC.registerInstance] Failed with: ${instance}`);
   }
 });
 
+ipcMain.on("removeInstance", (event, instance) => {
+  try {
+    const url = new URL(instance);
+    userInstances.delete(url.origin);
+  } catch (error) {
+    console.error(`[ERROR] [IPC.removeInstance] Failed with: ${instance}`);
+  }
+});
+
 app.on("web-contents-created", (event, contents) => {
   // Open links in a new tab or a browser, instead of a new window
   contents.setWindowOpenHandler(({ url }) => {
diff --git a/src/process/preload.js b/src/process/preload.js
index ca2e367..5843922 100644
--- a/src/process/preload.js
+++ b/src/process/preload.js
@@ -13,6 +13,7 @@ contextBridge.exposeInMainWorld(
         "OpenHelp",
         "OpenOffline",
         "registerInstance",
+        "removeInstance",
       ];
 
       if (validChannels.includes(channel)) {