diff --git a/assets/js/session-guard.js b/assets/js/session-guard.js
index 966711b..f75e9fd 100644
--- a/assets/js/session-guard.js
+++ b/assets/js/session-guard.js
@@ -1,9 +1,10 @@
 /**
- * Fociz Session Guard (Release v1.6)
+ * Fociz Session Guard (Release v1.6.1)
  * Realtime beveiligingsbeheer voor sessie-inactiviteit conform NIST SP 800-63B / ISO 27001
  * - Waarschuwt de gebruiker 2 minuten voor het verlopen met aftelklok
  * - Throttled keepalive pings tijdens actieve interactie
  * - Synchronisatie over meerdere open browsertabbladen via localStorage
+ * - Beschermd tegen oneindige herlaad- en redirect-loops
  */
 
 (function () {
@@ -17,20 +18,40 @@
     // Waarschuwing 120 seconden voor afloop (of de helft indien timeout kort is)
     var warningSeconds = idleTimeout > 240 ? 120 : Math.max(10, Math.floor(idleTimeout / 2));
 
-    var lastActivity = Date.now();
-    var lastPingTime = Date.now();
+    var now = Date.now();
+    var lastActivity = now;
+    var lastPingTime = now;
     var isWarningShowing = false;
     var keepaliveInFlight = false;
+    var hasRedirected = false;
 
-    // Synchronisatie met andere tabbladen
+    // Synchronisatie met andere tabbladen:
+    // Alleen een timestamp overnemen als deze GELDIG is en NIET al verlopen is!
+    // Aangezien DEZE pagina zojuist succesvol geladen is, is de sessie NU actief.
     var storedActivity = localStorage.getItem('fociz_session_last_activity');
     if (storedActivity) {
         var parsed = parseInt(storedActivity, 10);
-        if (!isNaN(parsed) && parsed > 0 && parsed <= Date.now()) {
-            lastActivity = parsed;
+        if (!isNaN(parsed) && parsed > 0 && parsed <= now && (now - parsed) < (idleTimeout * 1000)) {
+            lastActivity = Math.max(now, parsed);
         }
     }
 
+    // Direct opslaan zodat alle tabbladen weten dat er zojuist activiteit was
+    try {
+        localStorage.setItem('fociz_session_last_activity', lastActivity.toString());
+        localStorage.removeItem('fociz_session_logged_out');
+    } catch (e) {}
+
+    // Veilige eenmalige redirect helper om redirect loops te voorkomen
+    function redirectToExpired() {
+        if (hasRedirected) return;
+        hasRedirected = true;
+        try {
+            localStorage.setItem('fociz_session_logged_out', Date.now().toString());
+        } catch (e) {}
+        window.location.href = '/auth/login.php?expired=1';
+    }
+
     // Modal DOM elementen
     var modalEl = null;
     var countdownEl = null;
@@ -69,7 +90,13 @@
                 }
             }
         } else if (e.key === 'fociz_session_logged_out') {
-            window.location.href = '/auth/login.php?expired=1';
+            if (!hasRedirected) {
+                var loggedOutTime = parseInt(e.newValue, 10);
+                if (!isNaN(loggedOutTime) && Math.abs(Date.now() - loggedOutTime) < 10000) {
+                    hasRedirected = true;
+                    window.location.href = '/auth/login.php?expired=1';
+                }
+            }
         }
     });
 
@@ -104,7 +131,7 @@
 
     // Verzend keepalive naar de backend
     function sendKeepalive(manualClick) {
-        if (keepaliveInFlight) return;
+        if (hasRedirected || keepaliveInFlight) return;
         keepaliveInFlight = true;
 
         if (manualClick && keepaliveBtn) {
@@ -121,9 +148,8 @@
         })
         .then(function (res) {
             if (res.status === 401) {
-                // Reeds verlopen
-                localStorage.setItem('fociz_session_logged_out', Date.now().toString());
-                window.location.href = '/auth/login.php?expired=1';
+                // Reeds verlopen op de server
+                redirectToExpired();
                 return null;
             }
             return res.json();
@@ -136,9 +162,12 @@
             }
 
             if (data && data.success) {
-                lastActivity = Date.now();
-                lastPingTime = Date.now();
-                localStorage.setItem('fociz_session_last_activity', lastActivity.toString());
+                var currentNow = Date.now();
+                lastActivity = currentNow;
+                lastPingTime = currentNow;
+                try {
+                    localStorage.setItem('fociz_session_last_activity', currentNow.toString());
+                } catch (e) {}
                 hideModal();
             }
         })
@@ -154,7 +183,11 @@
 
     // Direct uitloggen
     function performLogout() {
-        localStorage.setItem('fociz_session_logged_out', Date.now().toString());
+        if (hasRedirected) return;
+        hasRedirected = true;
+        try {
+            localStorage.setItem('fociz_session_logged_out', Date.now().toString());
+        } catch (e) {}
         fetch('/api/session.php?action=logout', {
             method: 'POST',
             headers: { 'X-Requested-With': 'XMLHttpRequest' }
@@ -165,49 +198,49 @@
 
     // Registreer gebruikersactiviteit (throttled)
     function registerUserActivity() {
-        var now = Date.now();
+        if (hasRedirected) return;
+        var currentNow = Date.now();
 
-        // Controleer ALTIJD eerst of de sessie al verlopen was terwijl de gebruiker weg was (bijv. laptop slaapstand of inactiviteit)
-        var elapsedSec = Math.floor((now - lastActivity) / 1000);
+        // Controleer of de sessie al verlopen is (bijv. laptop uit slaapstand)
+        var elapsedSec = Math.floor((currentNow - lastActivity) / 1000);
         if (elapsedSec >= idleTimeout) {
-            localStorage.setItem('fociz_session_logged_out', now.toString());
-            window.location.href = '/auth/login.php?expired=1';
+            redirectToExpired();
             return;
         }
 
-        // Als de waarschuwingsmodal actief is, negeren we vage muisbewegingen;
-        // de gebruiker moet expliciet op 'Blijf Ingelogd' klikken conform beveiligingsnormen.
+        // Als de waarschuwingsmodal actief is, vereisen we expliciete klik op 'Blijf Ingelogd'
         if (isWarningShowing) return;
 
         // Lokale activiteit bijwerken (maximaal eens per 3 seconden wegschrijven)
-        if (now - lastActivity > 3000) {
-            lastActivity = now;
-            localStorage.setItem('fociz_session_last_activity', now.toString());
+        if (currentNow - lastActivity > 3000) {
+            lastActivity = currentNow;
+            try {
+                localStorage.setItem('fociz_session_last_activity', currentNow.toString());
+            } catch (e) {}
         }
 
-        // Server keepalive: stuur op de achtergrond een ping als er activiteit is
-        // én er minimaal 60 seconden (of idleTimeout / 4) sinds de vorige serverping is verstreken.
+        // Server keepalive ping (maximaal eens per 60 seconden)
         var minPingInterval = Math.min(60000, Math.max(15000, (idleTimeout * 1000) / 4));
-        if (now - lastPingTime > minPingInterval) {
-            lastPingTime = now;
+        if (currentNow - lastPingTime > minPingInterval) {
+            lastPingTime = currentNow;
             sendKeepalive(false);
         }
     }
 
     // Direct controleren bij terugkeer naar tabblad of ontwaken uit slaapstand
     function checkIdleOnWakeup() {
-        var now = Date.now();
-        var storedActivity = localStorage.getItem('fociz_session_last_activity');
-        if (storedActivity) {
-            var parsed = parseInt(storedActivity, 10);
-            if (!isNaN(parsed) && parsed > 0) {
+        if (hasRedirected) return;
+        var currentNow = Date.now();
+        var stored = localStorage.getItem('fociz_session_last_activity');
+        if (stored) {
+            var parsed = parseInt(stored, 10);
+            if (!isNaN(parsed) && parsed > 0 && parsed <= currentNow) {
                 lastActivity = Math.max(lastActivity, parsed);
             }
         }
-        var elapsedSec = Math.floor((now - lastActivity) / 1000);
+        var elapsedSec = Math.floor((currentNow - lastActivity) / 1000);
         if (elapsedSec >= idleTimeout) {
-            localStorage.setItem('fociz_session_logged_out', now.toString());
-            window.location.href = '/auth/login.php?expired=1';
+            redirectToExpired();
         }
     }
 
@@ -226,14 +259,13 @@
 
     // Hoofdtimer interval (elke seconde)
     function tick() {
-        var now = Date.now();
-        var elapsedSec = Math.floor((now - lastActivity) / 1000);
+        if (hasRedirected) return;
+        var currentNow = Date.now();
+        var elapsedSec = Math.floor((currentNow - lastActivity) / 1000);
         var remainingSec = idleTimeout - elapsedSec;
 
         if (remainingSec <= 0) {
-            // Sessie officieel verlopen
-            localStorage.setItem('fociz_session_logged_out', now.toString());
-            window.location.href = '/auth/login.php?expired=1';
+            redirectToExpired();
             return;
         }
 
@@ -257,4 +289,3 @@
         setInterval(tick, 1000);
     }
 })();
-
diff --git a/auth/login.php b/auth/login.php
index 94f8292..a0508ec 100644
--- a/auth/login.php
+++ b/auth/login.php
@@ -12,6 +12,18 @@ if (!has_admin_user()) {
     exit;
 }
 
+// Als de sessie verlopen, ingetrokken of gewijzigd is: beëindig deze direct en wis cookies
+if (isset($_GET['expired']) || isset($_GET['revoked']) || isset($_GET['ip_changed'])) {
+    if (!empty($_SESSION['user_id'])) {
+        fociz_terminate_session(session_id());
+    }
+    clear_day_session_cookie();
+    $_SESSION = [];
+    if (session_status() === PHP_SESSION_ACTIVE) {
+        @session_regenerate_id(true);
+    }
+}
+
 // Als al ingelogd (via actieve sessie of persistente cookie), ga direct naar planner
 $currentUser = get_logged_in_user();
 if ($currentUser) {
@@ -338,6 +350,10 @@ $pageTitle = "Fociz — Inloggen";
 </div>
 
 <script>
+    try {
+        localStorage.removeItem('fociz_session_last_activity');
+        localStorage.removeItem('fociz_session_logged_out');
+    } catch(e) {}
     if (typeof lucide !== 'undefined') lucide.createIcons();
 </script>
 </body>
diff --git a/includes/auth.php b/includes/auth.php
index 7effed8..47a4423 100644
--- a/includes/auth.php
+++ b/includes/auth.php
@@ -28,9 +28,6 @@ function is_https_request(): bool {
     if (isset($_SERVER['SERVER_PORT']) && (int)$_SERVER['SERVER_PORT'] === 443) {
         return true;
     }
-    if (defined('APP_URL') && str_starts_with(APP_URL, 'https://')) {
-        return true;
-    }
     return false;
 }
 
@@ -306,9 +303,8 @@ function start_secure_session(): void {
         ini_set('session.gc_maxlifetime', '86400');
         ini_set('session.cookie_httponly', '1');
 
-        // Cookie prefix: __Host- garandeert dat cookies niet door subdomeinen kunnen worden overschreven
-        $sessionName = $isSecure ? '__Host-fociz_session' : 'fociz_session';
-        session_name($sessionName);
+        // Sessienaam instellen (veilig en uniform)
+        session_name('fociz_session');
 
         session_set_cookie_params([
             'lifetime' => 0, // Browser sessiecookie: vervalt direct bij afsluiten browser conform ISO 27001 / NIST SP 800-63B
@@ -501,7 +497,12 @@ function fociz_is_session_active(string $sessionId, int $userId): bool {
         $stmt = $db->prepare("SELECT is_active, expires_at FROM user_sessions WHERE session_id_hash = ? AND user_id = ?");
         $stmt->execute([$hash, $userId]);
         $row = $stmt->fetch();
-        if (!$row) return true; // Als sessie nog niet geregistreerd staat, laat het door (wordt geregistreerd)
+        if (!$row) {
+            // Als sessie nog niet geregistreerd staat, registreer direct om tracking consistent te houden
+            $maxIdleSeconds = function_exists('get_session_idle_timeout') ? get_session_idle_timeout() : 1800;
+            fociz_register_active_session($userId, $sessionId, $maxIdleSeconds);
+            return true;
+        }
         return (!empty($row['is_active']));
     } catch (Throwable $e) {
         return true; // Fallback op toegestaan bij databaseverstoring
diff --git a/includes/header.php b/includes/header.php
index 81a1ccd..598e17b 100644
--- a/includes/header.php
+++ b/includes/header.php
@@ -64,9 +64,12 @@ $currentUserTheme = !empty($currentUser['id']) ? get_user_theme((int)$currentUse
     <script>
         (function() {
             try {
+                let hasRedirected = false;
                 const sessionExpiresAt = <?= strtotime('today 23:59:59') ?> * 1000;
                 const checkExpiry = function() {
+                    if (hasRedirected) return;
                     if (Date.now() > sessionExpiresAt + 1000) {
+                        hasRedirected = true;
                         window.location.href = '/auth/login.php?expired=1';
                     }
                 };