diff --git a/API/Controllers/NotificationConnectorController.cs b/API/Controllers/NotificationConnectorController.cs
index 157e0f5..70f74ef 100644
--- a/API/Controllers/NotificationConnectorController.cs
+++ b/API/Controllers/NotificationConnectorController.cs
@@ -48,30 +48,29 @@ public class NotificationConnectorController(NotificationsContext context) : Con
     /// Creates a new <see cref="NotificationConnector"/>
     /// </summary>
     /// <remarks>Formatting placeholders: "%title" and "%text" can be placed in url, header-values and body and will be replaced when notifications are sent</remarks>
-    /// <response code="201"></response>
+    /// <response code="200">ID of the new <see cref="NotificationConnector"/></response>
     /// <response code="500">Error during Database Operation</response>
     [HttpPut]
-    [ProducesResponseType(Status201Created)]
-    [ProducesResponseType(Status409Conflict)]
+    [ProducesResponseType<string>(Status200OK, "text/plain")]
     [ProducesResponseType<string>(Status500InternalServerError, "text/plain")]
     public IActionResult CreateConnector([FromBody]NotificationConnector notificationConnector)
     {
-        
         context.NotificationConnectors.Add(notificationConnector);
+        context.Notifications.Add(new ("Added new Notification Connector!", notificationConnector.Name, NotificationUrgency.High));
         
         if(context.Sync() is { success: false } result)
             return StatusCode(Status500InternalServerError, result.exceptionMessage);
-        return Created();
+        return Ok(notificationConnector.Name);
     }
     
     /// <summary>
     /// Creates a new Gotify-<see cref="NotificationConnector"/>
     /// </summary>
     /// <remarks>Priority needs to be between 0 and 10</remarks>
-    /// <response code="201"></response>
+    /// <response code="200">ID of the new <see cref="NotificationConnector"/></response>
     /// <response code="500">Error during Database Operation</response>
     [HttpPut("Gotify")]
-    [ProducesResponseType<string>(Status201Created, "application/json")]
+    [ProducesResponseType<string>(Status200OK, "text/plain")]
     [ProducesResponseType<string>(Status500InternalServerError, "text/plain")]
     public IActionResult CreateGotifyConnector([FromBody]GotifyRecord gotifyData)
     {
@@ -79,7 +78,7 @@ public class NotificationConnectorController(NotificationsContext context) : Con
         
         NotificationConnector gotifyConnector = new (gotifyData.Name,
             gotifyData.Endpoint, 
-            new Dictionary<string, string>() { { "X-Gotify-IDOnConnector", gotifyData.AppToken } }, 
+            new Dictionary<string, string>() { { "X-Gotify-Key", gotifyData.AppToken } }, 
             "POST", 
             $"{{\"message\": \"%text\", \"title\": \"%title\", \"Priority\": {gotifyData.Priority}}}");
         return CreateConnector(gotifyConnector);
@@ -89,10 +88,10 @@ public class NotificationConnectorController(NotificationsContext context) : Con
     /// Creates a new Ntfy-<see cref="NotificationConnector"/>
     /// </summary>
     /// <remarks>Priority needs to be between 1 and 5</remarks>
-    /// <response code="201"></response>
+    /// <response code="200">ID of the new <see cref="NotificationConnector"/></response>
     /// <response code="500">Error during Database Operation</response>
     [HttpPut("Ntfy")]
-    [ProducesResponseType<string>(Status201Created, "application/json")]
+    [ProducesResponseType<string>(Status200OK, "text/plain")]
     [ProducesResponseType<string>(Status500InternalServerError, "text/plain")]
     public IActionResult CreateNtfyConnector([FromBody]NtfyRecord ntfyRecord)
     {
@@ -102,14 +101,13 @@ public class NotificationConnectorController(NotificationsContext context) : Con
         string auth = Convert.ToBase64String(Encoding.UTF8.GetBytes(authHeader)).Replace("=","");
         
         NotificationConnector ntfyConnector = new (ntfyRecord.Name,
-            $"{ntfyRecord.Endpoint}/{ntfyRecord.Topic}?auth={auth}", 
+            $"{ntfyRecord.Endpoint}?auth={auth}", 
             new Dictionary<string, string>()
             {
-                {"Title", "%title"},
-                {"Priority", ntfyRecord.Priority.ToString()},
+                {"Authorization", auth}
             }, 
             "POST", 
-            "%text");
+            $"{{\"message\": \"%text\", \"title\": \"%title\", \"Priority\": {ntfyRecord.Priority} \"Topic\": \"{ntfyRecord.Topic}\"}}");
         return CreateConnector(ntfyConnector);
     }
     
@@ -117,10 +115,10 @@ public class NotificationConnectorController(NotificationsContext context) : Con
     /// Creates a new Pushover-<see cref="NotificationConnector"/>
     /// </summary>
     /// <remarks>https://pushover.net/api</remarks>
-    /// <response code="201">ID of new connector</response>
+    /// <response code="200">ID of the new <see cref="NotificationConnector"/></response>
     /// <response code="500">Error during Database Operation</response>
     [HttpPut("Pushover")]
-    [ProducesResponseType<string>(Status201Created, "application/json")]
+    [ProducesResponseType<string>(Status200OK, "text/plain")]
     [ProducesResponseType<string>(Status500InternalServerError, "text/plain")]
     public IActionResult CreatePushoverConnector([FromBody]PushoverRecord pushoverRecord)
     {
@@ -154,6 +152,6 @@ public class NotificationConnectorController(NotificationsContext context) : Con
         
         if(context.Sync() is { success: false } result)
             return StatusCode(Status500InternalServerError, result.exceptionMessage);
-        return Created();
+        return Ok();
     }
 }
\ No newline at end of file
diff --git a/API/Schema/NotificationsContext/NotificationConnectors/NotificationConnector.cs b/API/Schema/NotificationsContext/NotificationConnectors/NotificationConnector.cs
index a57b2ba..72e37ca 100644
--- a/API/Schema/NotificationsContext/NotificationConnectors/NotificationConnector.cs
+++ b/API/Schema/NotificationsContext/NotificationConnectors/NotificationConnector.cs
@@ -44,40 +44,29 @@ public class NotificationConnector(string name, string url, Dictionary<string, s
     public void SendNotification(string title, string notificationText)
     {
         Log.Info($"Sending notification: {title} - {notificationText}");
-        CustomWebhookFormatProvider formatProvider = new (title, notificationText);
-        string formattedUrl = string.Format(formatProvider, Url);
-        string formattedBody = string.Format(formatProvider, Body, title, notificationText);
+        string formattedUrl = FormatStr(Url, title, notificationText);
+        string formattedBody = FormatStr(Body, title, notificationText);
         Dictionary<string, string> formattedHeaders = Headers.ToDictionary(h => h.Key, 
-            h => string.Format(formatProvider, h.Value, title, notificationText));
+            h => FormatStr(h.Value, title, notificationText));
 
         HttpRequestMessage request = new(System.Net.Http.HttpMethod.Parse(HttpMethod), formattedUrl);
         foreach (var (key, value) in formattedHeaders)
             request.Headers.Add(key, value);
         request.Content = new StringContent(formattedBody);
+        request.Content.Headers.ContentType = new ("application/json");
         Log.Debug($"Request: {request}");
 
         HttpResponseMessage response = Client.Send(request);
-        Log.Debug($"Response status code: {response.StatusCode}");
+        Log.Debug($"Response status code: {response.StatusCode} {response.Content.ReadAsStringAsync().Result}");
     }
 
-    private class CustomWebhookFormatProvider(string title, string text) : IFormatProvider
+    private string FormatStr(string str, string title, string text)
     {
-        public object? GetFormat(Type? formatType)
-        {
-            return this;
-        }
-
-        public string Format(string fmt, object arg, IFormatProvider provider)
-        {
-            if(arg.GetType() != typeof(string))
-                return arg.ToString() ?? string.Empty;
-
-            StringBuilder sb = new StringBuilder(fmt);
-            sb.Replace("%title", title);
-            sb.Replace("%text", text);
+        StringBuilder sb = new (str);
+        sb.Replace("%title", title);
+        sb.Replace("%text", text);
             
-            return sb.ToString();
-        }
+        return sb.ToString();
     }
 
     public override string ToString() => $"{GetType().Name} {Name}";
diff --git a/API/Tranga.cs b/API/Tranga.cs
index 76d726e..406fb15 100644
--- a/API/Tranga.cs
+++ b/API/Tranga.cs
@@ -71,7 +71,7 @@ public static class Tranga
         return mangaConnector != null;
     }
     
-    internal static readonly Dictionary<IPeriodic, Task> PeriodicWorkers = new ();
+    internal static readonly ConcurrentDictionary<IPeriodic, Task> PeriodicWorkers = new ();
 
     public static void AddWorker(BaseWorker worker)
     {
@@ -84,8 +84,9 @@ public static class Tranga
     private static void AddPeriodicWorker(BaseWorker worker, IPeriodic periodic)
     {
         Log.Debug($"Adding Periodic {worker}");
-        PeriodicWorkers.Add((worker as IPeriodic)!, PeriodicTask(worker, periodic));
-        PeriodicWorkers[(worker as IPeriodic)!].Start();
+        Task periodicTask = PeriodicTask(worker, periodic);
+        PeriodicWorkers.TryAdd((worker as IPeriodic)!, periodicTask);
+        periodicTask.Start();
     }
 
     private static Task PeriodicTask(BaseWorker worker, IPeriodic periodic) => new (() =>
@@ -100,8 +101,9 @@ public static class Tranga
         if (worker.State < WorkerExecutionState.Created) //Failed
             return;
         Log.Debug($"Refreshing {worker}");
-        PeriodicWorkers[(worker as IPeriodic)!] = PeriodicTask(worker, periodic);
-        PeriodicWorkers[(worker as IPeriodic)!].Start();
+        Task periodicTask = PeriodicTask(worker, periodic);
+        PeriodicWorkers.AddOrUpdate((worker as IPeriodic)!, periodicTask, (_, _) => periodicTask);
+        periodicTask.Start();
     };
     
     public static void AddWorkers(IEnumerable<BaseWorker> workers)
@@ -149,7 +151,7 @@ public static class Tranga
     {
         Log.Debug($"Stopping {worker}");
         if(worker is IPeriodic periodicWorker)
-            PeriodicWorkers.Remove(periodicWorker);
+            PeriodicWorkers.Remove(periodicWorker, out _);
         worker.Cancel();
         RunningWorkers.Remove(worker, out _);
     }