diff --git a/diagnostic/server.js b/diagnostic/server.js
index 3686d4a..43f261f 100644
--- a/diagnostic/server.js
+++ b/diagnostic/server.js
@@ -448,7 +448,13 @@ function connectRVS(forcePlain) {
     return;
   }
 
-  // TLS-Logik: wss zuerst, bei Fehler Fallback auf ws (wenn erlaubt)
+  // Alte Verbindung sauber schliessen
+  if (rvsWs) {
+    try { rvsWs.removeAllListeners(); rvsWs.close(); } catch (_) {}
+    rvsWs = null;
+  }
+
+  // TLS-Logik: wss zuerst, bei Fehler Fallback auf ws
   const useTls = RVS_TLS === "true" && !forcePlain;
   const proto = useTls ? "wss" : "ws";
   const url = `${proto}://${RVS_HOST}:${RVS_PORT}?token=${RVS_TOKEN}`;
@@ -457,7 +463,18 @@ function connectRVS(forcePlain) {
   broadcastState();
   log("info", "rvs", `Verbinde: ${proto}://${RVS_HOST}:${RVS_PORT}`);
 
-  const ws = new WebSocket(url);
+  let ws;
+  try {
+    ws = new WebSocket(url);
+  } catch (err) {
+    log("error", "rvs", `WebSocket erstellen fehlgeschlagen: ${err.message}`);
+    if (useTls && RVS_TLS_FALLBACK === "true") {
+      connectRVS(true);
+    }
+    return;
+  }
+
+  let fallbackTriggered = false;
 
   ws.on("open", () => {
     log("info", "rvs", `Verbunden (${proto})`);
@@ -465,6 +482,16 @@ function connectRVS(forcePlain) {
     state.rvs.lastError = null;
     rvsWs = ws;
     broadcastState();
+
+    // Keepalive: alle 25s ein Ping senden damit die Verbindung nicht stirbt
+    const keepalive = setInterval(() => {
+      if (ws.readyState === WebSocket.OPEN) {
+        try { ws.ping(); } catch (_) {}
+      } else {
+        clearInterval(keepalive);
+      }
+    }, 25000);
+    ws._keepalive = keepalive;
   });
 
   ws.on("message", (raw) => {
@@ -487,10 +514,13 @@ function connectRVS(forcePlain) {
 
   ws.on("close", () => {
     log("warn", "rvs", "Verbindung geschlossen");
+    if (ws._keepalive) clearInterval(ws._keepalive);
     state.rvs.status = "disconnected";
-    rvsWs = null;
+    if (rvsWs === ws) rvsWs = null;
     broadcastState();
-    setTimeout(() => connectRVS(), 5000);
+    if (!fallbackTriggered) {
+      setTimeout(() => connectRVS(), 5000);
+    }
   });
 
   ws.on("error", (err) => {
@@ -498,11 +528,12 @@ function connectRVS(forcePlain) {
     state.rvs.lastError = err.message;
     broadcastState();
 
-    // TLS Fallback: wenn wss fehlschlaegt und Fallback erlaubt → ws versuchen
-    if (useTls && RVS_TLS_FALLBACK === "true") {
+    // TLS Fallback
+    if (useTls && RVS_TLS_FALLBACK === "true" && !fallbackTriggered) {
+      fallbackTriggered = true;
       log("warn", "rvs", "TLS fehlgeschlagen — Fallback auf ws://");
-      ws.removeAllListeners();
-      try { ws.close(); } catch (_) {}
+      try { ws.removeAllListeners(); ws.close(); } catch (_) {}
+      if (rvsWs === ws) rvsWs = null;
       connectRVS(true);
     }
   });