diff --git a/.env.development b/.env.development
index 4d3c5b6..96cb084 100644
--- a/.env.development
+++ b/.env.development
@@ -6,6 +6,6 @@ NEXT_PUBLIC_USE_MOCK_BACKEND_LOOP_START=false
 NEXT_PUBLIC_EXPORT_STATIC=false
 NEXT_PUBLIC_USE_CGI=false
 # App-Versionsnummer
-NEXT_PUBLIC_APP_VERSION=1.6.669
+NEXT_PUBLIC_APP_VERSION=1.6.670
 NEXT_PUBLIC_CPL_MODE=json   # json (Entwicklungsumgebung) oder jsSimulatedProd (CPL ->CGI-Interface-Simulator) oder production (CPL-> CGI-Interface Platzhalter)
 
diff --git a/.env.production b/.env.production
index fc1d116..c21f9c4 100644
--- a/.env.production
+++ b/.env.production
@@ -5,5 +5,5 @@ NEXT_PUBLIC_CPL_API_PATH=/CPL
 NEXT_PUBLIC_EXPORT_STATIC=true
 NEXT_PUBLIC_USE_CGI=true
 # App-Versionsnummer
-NEXT_PUBLIC_APP_VERSION=1.6.669
+NEXT_PUBLIC_APP_VERSION=1.6.670
 NEXT_PUBLIC_CPL_MODE=production
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d882018..a705277 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,25 @@
+## [1.6.670] – 2025-07-31
+
+- feat: implement modal chart system with conditional UI and message filtering
+
+- Add automatic data loading on IsoChartView modal open with timeout to prevent infinite loops
+- Implement conditional UI visibility in IsoChartActionBar using CSS visibility property
+- Create stable layout where controls reserve space when hidden (DatePicker, DIA dropdown, "Daten laden" button)
+- Add Report.tsx component with precise CableLine filtering using exact string matching
+- Enhance message filtering with debug logging and fallback identifier support
+- Integrate chartTitle state management for seamless switching between "Messkurve" and "Meldungen"
+- Add useIsoDataLoader hook for automatic chart data loading without user interaction
+- Implement enhanced filtering logic to prevent false matches (CableLine1 vs CableLine16)
+- Style Report component with consistent table layout matching MeldungenView design
+- Add visual filter indicators and improved error messaging for better UX
+
+Technical improvements:
+- Replace conditional rendering with visibility control to maintain layout stability
+- Add comprehensive logging for debugging message source filtering
+- Implement proper cleanup for timeouts to prevent memory leaks
+- Use exact string matching and prefix validation for precise slot identification
+
+---
 ## [1.6.669] – 2025-07-31
 
 - feat: Meldungen in in Iso Chart
diff --git a/components/header/Header.tsx b/components/header/Header.tsx
index 50bb973..c2bcdc7 100644
--- a/components/header/Header.tsx
+++ b/components/header/Header.tsx
@@ -110,16 +110,17 @@ function Header() {
           */}
         </div>
 
-        {/* Logout-Button */}
-
-        <div className="flex items-center justify-end w-1/4 space-x-1">
-          <button
-            onClick={handleLogout}
-            className="bg-littwin-blue text-white px-4 py-2 rounded"
-          >
-            Abmelden
-          </button>
-        </div>
+        {/* Logout-Button - nur anzeigen wenn Admin eingeloggt ist */}
+        {isAdminLoggedIn && (
+          <div className="flex items-center justify-end w-1/4 space-x-1">
+            <button
+              onClick={handleLogout}
+              className="bg-littwin-blue text-white px-4 py-2 rounded"
+            >
+              Abmelden
+            </button>
+          </div>
+        )}
       </div>
 
       {/* Warnhinweis, wenn der Admin angemeldet ist */}
diff --git a/package-lock.json b/package-lock.json
index e9ca364..603e532 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "cpl-v4",
-  "version": "1.6.669",
+  "version": "1.6.670",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "cpl-v4",
-      "version": "1.6.669",
+      "version": "1.6.670",
       "dependencies": {
         "@fontsource/roboto": "^5.1.0",
         "@headlessui/react": "^2.2.4",
diff --git a/package.json b/package.json
index c186052..1cd2a40 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cpl-v4",
-  "version": "1.6.669",
+  "version": "1.6.670",
   "private": true,
   "scripts": {
     "dev": "next dev",