diff --git a/lib/screens/scanner_screen.dart b/lib/screens/scanner_screen.dart
index 3222168..f8eece9 100644
--- a/lib/screens/scanner_screen.dart
+++ b/lib/screens/scanner_screen.dart
@@ -25,6 +25,11 @@ class ScannerScreen extends StatefulWidget {
 
 class _ScannerScreenState extends State<ScannerScreen> {
   bool _changedNavigation = false;
+
+  /// Re-entrancy guard for routing into the app. Distinct from
+  /// [_changedNavigation], which records that we entered at least once and
+  /// gates the disconnect-on-dispose cleanup.
+  bool _routingIntoApp = false;
   late final MeshCoreConnector _connector;
   late final VoidCallback _connectionListener;
   BluetoothAdapterState _bluetoothState = BluetoothAdapterState.unknown;
@@ -42,12 +47,21 @@ class _ScannerScreenState extends State<ScannerScreen> {
       } else if (_connector.state == MeshCoreConnectionState.connected &&
           _connector.activeTransport == MeshCoreTransportType.bluetooth &&
           isCurrentRoute &&
-          !_changedNavigation) {
+          !_routingIntoApp) {
+        // Route in whenever this screen is showing while connected, not just
+        // on the first connect. Otherwise landing back here with a live
+        // connection is a dead end: Connect does nothing, because there is
+        // nothing left to connect.
         _changedNavigation = true;
+        _routingIntoApp = true;
         if (mounted) {
-          Navigator.of(context).push(
-            MaterialPageRoute(builder: (context) => const ChannelsScreen()),
-          );
+          Navigator.of(context)
+              .push(
+                MaterialPageRoute(builder: (context) => const ChannelsScreen()),
+              )
+              .then((_) {
+                if (mounted) _routingIntoApp = false;
+              });
         }
       }
     };
diff --git a/lib/widgets/app_shell.dart b/lib/widgets/app_shell.dart
index 689caa3..b95ba8d 100644
--- a/lib/widgets/app_shell.dart
+++ b/lib/widgets/app_shell.dart
@@ -68,21 +68,27 @@ class _AppShellState extends State<AppShell> {
 
   /// System back, in priority order:
   ///   1. an open drawer closes,
-  ///   2. otherwise pop the route (a pushed chat returns to its list),
-  ///   3. otherwise hand back to the OS, so Android returns to the home
-  ///      screen or the previous app rather than sitting on a dead press.
+  ///   2. on a detail screen, pop back to the list it came from,
+  ///   3. on a primary view, hand back to the OS so Android returns to the
+  ///      home screen or the previous app.
   ///
-  /// Screens previously did this with `PopScope(canPop: !isConnected)`, which
-  /// swallowed back entirely while connected: the drawer would not close and
-  /// the app would never background.
+  /// Step 3 must NOT pop, even though the route below can be popped. The
+  /// primary views sit on top of the scanner, so popping would dump a
+  /// connected user back onto the radio-connect list. Reaching the scanner is
+  /// what Disconnect is for, not what Back is for.
+  ///
+  /// A primary view is one carrying the bottom bar; a detail screen (a channel
+  /// chat) has no [selectedIndex] and is genuinely pushed.
   void _handleBack() {
     final scaffold = _scaffoldKey.currentState;
     if (scaffold?.isDrawerOpen ?? false) {
       scaffold!.closeDrawer();
       return;
     }
+
+    final isPrimaryView = widget.selectedIndex != null;
     final navigator = Navigator.of(context);
-    if (navigator.canPop()) {
+    if (!isPrimaryView && navigator.canPop()) {
       navigator.pop();
       return;
     }