diff --git a/web/CertificatesPanel.tsx b/web/CertificatesPanel.tsx
index 066b91b..83afa41 100644
--- a/web/CertificatesPanel.tsx
+++ b/web/CertificatesPanel.tsx
@@ -2,6 +2,7 @@ import { useCallback, useEffect, useRef, useState } from "react";
 import { RefreshCw, ShieldAlert, ShieldCheck } from "lucide-react";
 import { useClient } from "hooks/useClient";
 import { readableError } from "./errors";
+import { useConnectionChanged } from "./channel";
 
 /**
  * Certificates, ordered by how soon they expire.
@@ -29,6 +30,7 @@ export const CertificatesPanel = () => {
   const clientRef = useRef(client);
   clientRef.current = client;
 
+  const [connectionSignal] = useConnectionChanged();
   const [certificates, setCertificates] = useState<Certificate[] | null>(null);
   const [error, setError] = useState<string | null>(null);
 
@@ -46,7 +48,7 @@ export const CertificatesPanel = () => {
 
   useEffect(() => {
     void load();
-  }, [load]);
+  }, [load, connectionSignal]);
 
   if (error) return <Centred>{error}</Centred>;
   if (!certificates) return <Centred>Loading certificates…</Centred>;
diff --git a/web/ConnectionPanel.tsx b/web/ConnectionPanel.tsx
index 2362940..a1816c0 100644
--- a/web/ConnectionPanel.tsx
+++ b/web/ConnectionPanel.tsx
@@ -4,6 +4,8 @@ import { useClient } from 'hooks/useClient';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { readableError } from './errors';
+import { useConnectionChanged } from './channel';
+import { useSearchParams } from 'react-router';
 
 /**
  * The connection to Nginx Proxy Manager — both the setup wizard and the permanent settings page.
@@ -115,6 +117,26 @@ export const ConnectionPanel = () => {
   const [error, setError] = useState<string | null>(null);
   const [busy, setBusy] = useState<'test' | 'save' | 'delete' | null>(null);
   const [confirming, setConfirming] = useState(false);
+  const [, connectionChanged] = useConnectionChanged();
+  const [, setParams] = useSearchParams();
+
+  /**
+   * Leave the settings view and tell the other panels to re-read.
+   *
+   * Both halves were missing and both were visible: after a successful save the form stayed open, and the
+   * hosts and certificates panels went on showing the failure they had loaded before a connection existed.
+   * The only remedy was a manual page refresh, which is what got reported.
+   */
+  const settled = useCallback(() => {
+    setParams(
+      (p) => {
+        p.delete('config');
+        return p;
+      },
+      { replace: true },
+    );
+    connectionChanged();
+  }, [setParams, connectionChanged]);
 
   const load = useCallback(async () => {
     try {
@@ -168,6 +190,7 @@ export const ConnectionPanel = () => {
       setView(next);
       setSecret('');
       setTest(null);
+      settled();
     } catch (err) {
       setError(errorText(err));
     } finally {
@@ -184,6 +207,8 @@ export const ConnectionPanel = () => {
       setTest(null);
       setSecret('');
       await load();
+      // Disconnecting is a change too — the panels must stop showing hosts that are no longer reachable.
+      connectionChanged();
     } catch (err) {
       setError(errorText(err));
     } finally {
diff --git a/web/HostsPanel.tsx b/web/HostsPanel.tsx
index cf26a46..83055a3 100644
--- a/web/HostsPanel.tsx
+++ b/web/HostsPanel.tsx
@@ -4,6 +4,7 @@ import { useClient } from "hooks/useClient";
 import { useSearchParams } from "react-router";
 import { ConnectionPanel } from "./ConnectionPanel";
 import { readableError } from "./errors";
+import { useConnectionChanged } from "./channel";
 
 /**
  * The proxy hosts, which is the thing anybody opens this plugin to see.
@@ -66,6 +67,9 @@ export const HostsPanel = () => {
   // `?config=1` is the settings page; an unconfigured plugin shows it whether or not it was asked for.
   // In the URL rather than in state, so it survives a refresh and can be linked to — `docs/navigation-audit.md`.
   const configuring = params.get("config") === "1";
+  // Re-read when the connection is saved or removed. Named as an effect dependency below — that IS the
+  // subscription; there is nothing to unsubscribe from.
+  const [connectionSignal] = useConnectionChanged();
 
   const load = useCallback(async () => {
     try {
@@ -79,7 +83,7 @@ export const HostsPanel = () => {
 
   useEffect(() => {
     void load();
-  }, [load]);
+  }, [load, connectionSignal]);
 
   const toggle = async (host: ProxyHost) => {
     setBusy(host.id);
diff --git a/web/channel.ts b/web/channel.ts
new file mode 100644
index 0000000..8ce852c
--- /dev/null
+++ b/web/channel.ts
@@ -0,0 +1,43 @@
+import { useCallback, useRef } from 'react';
+import { defineChannel } from 'hooks/usePanelChannel';
+
+/**
+ * "The connection changed — anyone reading NPM should read it again."
+ *
+ * ── Why a channel and not the URL ──
+ *
+ * `docs/navigation-audit.md` draws the line: anything ADDRESSABLE goes in the URL, and a channel is only
+ * for a signal — "something changed, re-read it". This is the second kind. Nobody wants to link to "the
+ * moment after the connection was saved", and there is nothing to select.
+ *
+ * ── Why it is needed at all ──
+ *
+ * The panels are siblings in a workspace layout. `ConnectionPanel` cannot call into `CertificatesPanel`
+ * and should not try — they are mounted independently and neither owns the other. Before this, saving a
+ * connection left both panels showing whatever they had failed to load a minute earlier, and the only fix
+ * a person had was a manual refresh. Reported on 2026-08-25 the first time a connection was saved through
+ * the form.
+ *
+ * ── The nonce is a plain counter, and that is not an accident ──
+ *
+ * Copied deliberately from `officerdev/src/channels.ts`, which records why. `setSignal(n => n + 1)` is
+ * WRONG here: the functional setter applies against the value captured at render, so two bumps inside one
+ * render window both compute `snapshot + 1` and the second silently overwrites the first — nobody
+ * re-reads. `Date.now()` has the same flaw in miniature, two bumps in one millisecond being one number.
+ * A module counter never reads React state, so it cannot be wrong however often it is called.
+ */
+const useConnectionChangedChannel = defineChannel<number>('proxy-manager:connection-changed', 0);
+
+let nonce = 0;
+
+export const useConnectionChanged = () => {
+  const [signal, setSignal] = useConnectionChangedChannel();
+
+  // The setter is a fresh closure every render and this `bump` goes into dependency lists, so it is read
+  // through a ref — stable identity without freezing the first render's setter.
+  const setRef = useRef(setSignal);
+  setRef.current = setSignal;
+  const bump = useCallback(() => setRef.current(++nonce), []);
+
+  return [signal, bump] as const;
+};