diff --git a/src/Web/autopilot-monitor-web/components/WhatsNewPanelHost.tsx b/src/Web/autopilot-monitor-web/components/WhatsNewPanelHost.tsx
index 4863aa05..da60e5b2 100644
--- a/src/Web/autopilot-monitor-web/components/WhatsNewPanelHost.tsx
+++ b/src/Web/autopilot-monitor-web/components/WhatsNewPanelHost.tsx
@@ -1,12 +1,13 @@
 "use client";
 
-import { useEffect } from "react";
-import { usePathname } from "next/navigation";
+import { Suspense, useEffect, useRef } from "react";
+import { usePathname, useSearchParams } from "next/navigation";
 import { WhatsNewPanel } from "./WhatsNewPanel";
 import { useWhatsNewState, openWhatsNew } from "@/lib/whatsNewStore";
 import { trackEvent } from "@/lib/appInsights";
 import { isPublicPath } from "@/lib/hostRouting";
 import { WHATS_NEW_CHANNELS, type WhatsNewChannel } from "@/lib/whatsNew";
+import { useAuth } from "@/contexts/AuthContext";
 
 /**
  * Mounts the What's new panel once, in the root layout, so the portal navbar, the landing
@@ -24,16 +25,43 @@ export function WhatsNewPanelHost() {
   const pathname = usePathname();
   const onPublicPage = isPublicPath(pathname);
 
+  return (
+    <>
+      {/* useSearchParams() needs a Suspense boundary for the static prerender. */}
+      <Suspense fallback={null}>
+        <WhatsNewDeepLink onPublicPage={onPublicPage} />
+      </Suspense>
+      {panelOpen && <WhatsNewPanel rootClassName={onPublicPage ? "landing-v2" : undefined} />}
+    </>
+  );
+}
+
+/**
+ * Opens the panel once each time `?whats-new=` arrives, not only on the first mount: a portal
+ * link opened without a session goes through the sign-in, which lands on the origin root and
+ * reaches the link again by a client-side navigation (AuthGate), where this layout stays
+ * mounted. A protected page waits for the session, so the panel neither flashes before the
+ * sign-in redirect nor counts the open twice.
+ */
+function WhatsNewDeepLink({ onPublicPage }: { onPublicPage: boolean }) {
+  const requested = useSearchParams()?.get("whats-new") ?? null;
+  const { isAuthenticated, isLoading } = useAuth();
+  const ready = onPublicPage || (isAuthenticated && !isLoading);
+  const handled = useRef(false);
+
   useEffect(() => {
-    const requested = new URLSearchParams(window.location.search).get("whats-new");
-    if (requested === null) return;
+    if (requested === null) {
+      handled.current = false;
+      return;
+    }
+    if (handled.current || !ready) return;
+    handled.current = true;
     const channel = (WHATS_NEW_CHANNELS as readonly string[]).includes(requested)
       ? (requested as WhatsNewChannel)
       : undefined;
     trackEvent("whats_new_opened", { source: "deeplink", channel: channel ?? "default" });
     openWhatsNew("deeplink", channel);
-  }, []);
+  }, [requested, ready]);
 
-  if (!panelOpen) return null;
-  return <WhatsNewPanel rootClassName={onPublicPage ? "landing-v2" : undefined} />;
+  return null;
 }