diff --git a/extension/action_popup.html b/extension/action_popup.html
--- a/extension/action_popup.html
+++ b/extension/action_popup.html
@@ -33,6 +33,8 @@
 
         <p data-i18n="general_error_startup_failed">I18N</p>
 
+        <h4 id="startup_error_text" class="hidden"></h4>
+
         <a data-i18n="general_error_startup_failed_wiki_link" href="https://community.kde.org/Plasma/Browser_Integration" target="_blank">I18N</a>
     </div>
 
diff --git a/extension/action_popup.js b/extension/action_popup.js
--- a/extension/action_popup.js
+++ b/extension/action_popup.js
@@ -159,11 +159,20 @@
             document.getElementById("unsupported_os_error").classList.remove("hidden");
             break;
 
-        case "STARTUP_FAILED":
+        case "STARTUP_FAILED": {
             document.getElementById("startup_error").classList.remove("hidden");
+
+            const errorText = status.portLastErrorMessage;
+            // Don't show generic error on startup failure. There's already an explanation.
+            if (errorText && errorText !== "UNKNOWN") {
+                const errorTextItem = document.getElementById("startup_error_text");
+                errorTextItem.innerText = errorText;
+                errorTextItem.classList.remove("hidden");
+            }
             break;
+        }
 
-        default:
+        default: {
             document.getElementById("main").classList.remove("hidden");
 
             let errorText = status.portLastErrorMessage;
@@ -181,6 +190,7 @@
 
             break;
         }
+        }
 
         // HACK so the extension can tell we closed, see "browserAction" "ready" callback in extension.js
         chrome.runtime.onConnect.addListener((port) => {
diff --git a/extension/extension.js b/extension/extension.js
--- a/extension/extension.js
+++ b/extension/extension.js
@@ -97,7 +97,7 @@
         });
     }
 
-    if (portLastErrorMessage) {
+    if (portLastErrorMessage && receivedMessageOnce) {
         chrome.browserAction.setBadgeText({ text: "!" });
         chrome.browserAction.setBadgeBackgroundColor({ color: "#da4453" }); // breeze "negative" color
     } else {
@@ -180,14 +180,13 @@
         }
         kdeConnectDevices = {};
 
+        portLastErrorMessage = error && error.message || "UNKNOWN";
         if (receivedMessageOnce) {
-            portLastErrorMessage = error && error.message || "UNKNOWN";
             portStatus = "DISCONNECTED";
 
             console.log("Auto-restarting it");
             connectHost();
         } else {
-            portLastErrorMessage = "";
             portStatus = "STARTUP_FAILED";
 
             console.warn("Not auto-restarting host as we haven't received any message from it before. Check that it's working/installed correctly");
@@ -242,7 +241,10 @@
 
         // disabling the browser action immediately when opening it
         // causes opening to fail on Firefox, so clear the error only when it's being closed.
-        portLastErrorMessage = "";
-        updateBrowserAction();
+        // Only clear error when it was a transient error, not a startup failure
+        if (receivedMessageOnce) {
+            portLastErrorMessage = "";
+            updateBrowserAction();
+        }
     });
 });