diff --git a/app/src/main/java/com/nextcloud/talk/controllers/CallController.java b/app/src/main/java/com/nextcloud/talk/controllers/CallController.java
index 2d20f6417..4c6b7be0e 100644
--- a/app/src/main/java/com/nextcloud/talk/controllers/CallController.java
+++ b/app/src/main/java/com/nextcloud/talk/controllers/CallController.java
@@ -220,11 +220,7 @@ public class CallController extends BaseController {
         conversationPassword = args.getString(BundleKeys.KEY_CONVERSATION_PASSWORD, "");
         isVoiceOnlyCall = args.getBoolean(BundleKeys.KEY_CALL_VOICE_ONLY, false);
 
-        if (conversationUser.getUserId().equals("?")) {
-            credentials = null;
-        } else {
-            credentials = ApiUtils.getCredentials(conversationUser.getUsername(), conversationUser.getToken());
-        }
+        credentials = ApiUtils.getCredentials(conversationUser.getUsername(), conversationUser.getToken());
 
         baseUrl = args.getString(BundleKeys.KEY_MODIFIED_BASE_URL, "");
 
@@ -1158,7 +1154,8 @@ public class CallController extends BaseController {
         webSocketConnectionHelper = new WebSocketConnectionHelper();
         webSocketClient = webSocketConnectionHelper.getExternalSignalingInstanceForServer(
                 externalSignalingServer.getExternalSignalingServer(),
-                conversationUser, externalSignalingServer.getExternalSignalingTicket());
+                conversationUser, externalSignalingServer.getExternalSignalingTicket(),
+                TextUtils.isEmpty(credentials));
 
         if (webSocketClient.isConnected()) {
             joinRoomAndCall();
@@ -1336,6 +1333,11 @@ public class CallController extends BaseController {
         localAudioTrack = null;
         localVideoTrack = null;
 
+
+        if (TextUtils.isEmpty(credentials) && hasExternalSignalingServer) {
+            WebSocketConnectionHelper.deleteExternalSignalingInstanceForUserEntity(-1);
+        }
+
         if (!dueToNetworkChange) {
             hangupNetworkCalls();
         } else {
diff --git a/app/src/main/java/com/nextcloud/talk/controllers/ChatController.java b/app/src/main/java/com/nextcloud/talk/controllers/ChatController.java
index 953365f2d..c3c86ea2e 100644
--- a/app/src/main/java/com/nextcloud/talk/controllers/ChatController.java
+++ b/app/src/main/java/com/nextcloud/talk/controllers/ChatController.java
@@ -892,7 +892,7 @@ public class ChatController extends BaseController implements MessagesListAdapte
                     chatMessage.setLinkPreviewAllowed(isLinkPreviewAllowed);
 
                     // if credentials are empty, we're acting as a guest
-                    if (TextUtils.isEmpty(credentials) && !TextUtils.isEmpty(myFirstMessage.toString())) {
+                    if (TextUtils.isEmpty(credentials) && myFirstMessage != null && !TextUtils.isEmpty(myFirstMessage.toString())) {
                         if (chatMessage.getActorType().equals("guests")) {
                             conversationUser.setUserId(chatMessage.getActorId());
                             setSenderId();
diff --git a/app/src/main/java/com/nextcloud/talk/jobs/WebsocketConnectionsWorker.java b/app/src/main/java/com/nextcloud/talk/jobs/WebsocketConnectionsWorker.java
index 31a84f805..8e17c07ce 100644
--- a/app/src/main/java/com/nextcloud/talk/jobs/WebsocketConnectionsWorker.java
+++ b/app/src/main/java/com/nextcloud/talk/jobs/WebsocketConnectionsWorker.java
@@ -70,7 +70,8 @@ public class WebsocketConnectionsWorker extends Worker {
                             !TextUtils.isEmpty(externalSignalingServer.getExternalSignalingTicket())) {
                         webSocketConnectionHelper.getExternalSignalingInstanceForServer(
                                 externalSignalingServer.getExternalSignalingServer(),
-                                userEntity, externalSignalingServer.getExternalSignalingTicket());
+                                userEntity, externalSignalingServer.getExternalSignalingTicket(),
+                                false);
                     }
                 } catch (IOException e) {
                     Log.e(TAG, "Failed to parse external signaling server");
diff --git a/app/src/main/java/com/nextcloud/talk/utils/ApiUtils.java b/app/src/main/java/com/nextcloud/talk/utils/ApiUtils.java
index dc96530f4..4512e4880 100644
--- a/app/src/main/java/com/nextcloud/talk/utils/ApiUtils.java
+++ b/app/src/main/java/com/nextcloud/talk/utils/ApiUtils.java
@@ -20,8 +20,8 @@
 package com.nextcloud.talk.utils;
 
 import android.net.Uri;
-import androidx.annotation.DimenRes;
-import androidx.annotation.Nullable;
+
+import android.text.TextUtils;
 import com.nextcloud.talk.BuildConfig;
 import com.nextcloud.talk.R;
 import com.nextcloud.talk.application.NextcloudTalkApplication;
@@ -209,6 +209,9 @@ public class ApiUtils {
     }
 
     public static String getCredentials(String username, String token) {
+        if (TextUtils.isEmpty(username) && TextUtils.isEmpty(token)) {
+            return null;
+        }
         return Credentials.basic(username, token);
     }
 
diff --git a/app/src/main/java/com/nextcloud/talk/webrtc/WebSocketConnectionHelper.java b/app/src/main/java/com/nextcloud/talk/webrtc/WebSocketConnectionHelper.java
index 3fdc35f89..90daee0d9 100644
--- a/app/src/main/java/com/nextcloud/talk/webrtc/WebSocketConnectionHelper.java
+++ b/app/src/main/java/com/nextcloud/talk/webrtc/WebSocketConnectionHelper.java
@@ -44,7 +44,7 @@ public class WebSocketConnectionHelper {
         NextcloudTalkApplication.getSharedApplication().getComponentApplication().inject(this);
     }
 
-    public static synchronized MagicWebSocketInstance getExternalSignalingInstanceForServer(String url, UserEntity userEntity, String webSocketTicket) {
+    public static synchronized MagicWebSocketInstance getExternalSignalingInstanceForServer(String url, UserEntity userEntity, String webSocketTicket, boolean isGuest) {
         String generatedURL = url.replace("https://", "wss://").replace("http://", "ws://");
 
         if (generatedURL.endsWith("/")) {
@@ -53,10 +53,16 @@ public class WebSocketConnectionHelper {
             generatedURL += "/spreed";
         }
 
+        long userId = isGuest ? -1 : userEntity.getId();
+
+
         MagicWebSocketInstance magicWebSocketInstance;
-        if (magicWebSocketInstanceMap.containsKey(userEntity.getId()) && (magicWebSocketInstance = magicWebSocketInstanceMap.get(userEntity.getId())) != null && !magicWebSocketInstance.isPermanentlyClosed()) {
+        if (userId != -1 && magicWebSocketInstanceMap.containsKey(userEntity.getId()) && (magicWebSocketInstance = magicWebSocketInstanceMap.get(userEntity.getId())) != null && !magicWebSocketInstance.isPermanentlyClosed()) {
             return magicWebSocketInstance;
         } else {
+            if (userId == -1) {
+                deleteExternalSignalingInstanceForUserEntity(userId);
+            }
             magicWebSocketInstance = new MagicWebSocketInstance(userEntity, generatedURL, webSocketTicket);
             magicWebSocketInstanceMap.put(userEntity.getId(), magicWebSocketInstance);
             return magicWebSocketInstance;