diff --git a/API/Controllers/JobController.cs b/API/Controllers/JobController.cs
index 2ccb3a2..a469c12 100644
--- a/API/Controllers/JobController.cs
+++ b/API/Controllers/JobController.cs
@@ -152,7 +152,7 @@ public class JobController(PgsqlContext context) : Controller
         {
             context.Jobs.Add(job);
             context.SaveChanges();
-            return Created();
+            return new CreatedResult(job.JobId, job);
         }
         catch (Exception e)
         {
@@ -193,11 +193,15 @@ public class JobController(PgsqlContext context) : Controller
     /// Starts the Job with the requested ID
     /// </summary>
     /// <param name="id">Job-ID</param>
-    /// <returns>Nothing</returns>
+    /// <response code="202">Job started</response>
+    /// <response code="404">Job with ID not found</response>
+    /// <response code="409">Job was already running</response>
+    /// <response code="500">Internal Error</response>
     [HttpPost("{id}/Start")]
-    [ProducesResponseType(Status202Accepted)]
-    [ProducesResponseType(Status404NotFound)]
-    [ProducesResponseType(Status500InternalServerError)]
+    [ProducesResponseType<AcceptedResult>(Status202Accepted)]
+    [ProducesResponseType<NotFoundResult>(Status404NotFound)]
+    [ProducesResponseType<ConflictResult>(Status409Conflict)]
+    [ProducesResponseType<ObjectResult>(Status500InternalServerError)]
     public IActionResult StartJob(string id)
     {
         Job? ret = context.Jobs.Find(id);
@@ -205,7 +209,9 @@ public class JobController(PgsqlContext context) : Controller
             return NotFound();
         try
         {
-            context.Update(ret);
+            if (ret.state >= JobState.Running && ret.state < JobState.Completed)
+                return new ConflictResult();
+            ret.LastExecution = DateTime.UnixEpoch;
             context.SaveChanges();
             return Accepted();
         }
@@ -215,6 +221,19 @@ public class JobController(PgsqlContext context) : Controller
         }
     }
 
+    /// <summary>
+    /// NOT IMPLEMENTED. Stops the Job with the requested ID
+    /// </summary>
+    /// <param name="id">Job-ID</param>
+    /// <response code="202">Job started</response>
+    /// <response code="404">Job with ID not found</response>
+    /// <response code="409">Job was not running</response>
+    /// <response code="500">Internal Error</response>
+    /// <remarks>NOT IMPLEMENTED</remarks>
+    [ProducesResponseType<AcceptedResult>(Status202Accepted)]
+    [ProducesResponseType<NotFoundResult>(Status404NotFound)]
+    [ProducesResponseType<ConflictResult>(Status409Conflict)]
+    [ProducesResponseType<ObjectResult>(Status500InternalServerError)]
     [HttpPost("{id}/Stop")]
     public IActionResult StopJob(string id)
     {
diff --git a/API/Schema/Jobs/Job.cs b/API/Schema/Jobs/Job.cs
index e5c078e..fc23512 100644
--- a/API/Schema/Jobs/Job.cs
+++ b/API/Schema/Jobs/Job.cs
@@ -49,8 +49,10 @@ public abstract class Job
         PgsqlContext context = scope.ServiceProvider.GetRequiredService<PgsqlContext>();
         
         this.state = JobState.Running;
+        context.SaveChanges();
         IEnumerable<Job> newJobs = RunInternal(context);
         this.state = JobState.Completed;
+        context.SaveChanges();
         return newJobs;
     }
     
diff --git a/API/Tranga.cs b/API/Tranga.cs
index e494fb3..9c15dc4 100644
--- a/API/Tranga.cs
+++ b/API/Tranga.cs
@@ -69,7 +69,7 @@ public static class Tranga
         Log.Info(TRANGA);
         while (true)
         {
-            List<Job> completedJobs = context.Jobs.Where(j => j.state == JobState.Completed).ToList();
+            List<Job> completedJobs = context.Jobs.Where(j => j.state >= JobState.Completed && j.state < JobState.Failed).ToList();
             foreach (Job job in completedJobs)
                 if (job.RecurrenceMs <= 0)
                     context.Jobs.Remove(job);
@@ -87,6 +87,25 @@ public static class Tranga
                 // If the job is already running, skip it
                 if (RunningJobs.Values.Any(j => j.JobId == job.JobId)) continue;
 
+                if (job is DownloadNewChaptersJob dncj)
+                {
+                    if (RunningJobs.Values.Any(j =>
+                            j is DownloadNewChaptersJob rdncj &&
+                            rdncj.Manga?.MangaConnector == dncj.Manga?.MangaConnector))
+                    {
+                        continue;
+                    }
+                }
+                else if (job is DownloadSingleChapterJob dscj)
+                {
+                    if (RunningJobs.Values.Any(j =>
+                            j is DownloadSingleChapterJob rdscj && rdscj.Chapter?.ParentManga?.MangaConnector ==
+                            dscj.Chapter?.ParentManga?.MangaConnector))
+                    {
+                        continue;
+                    }
+                }
+
                 Thread t = new(() =>
                 {
                     IEnumerable<Job> newJobs = job.Run(serviceProvider);