diff --git a/Emby.Server.Implementations/Data/ManagedConnection.cs b/Emby.Server.Implementations/Data/ManagedConnection.cs
index 44dad5b17..11e33278d 100644
--- a/Emby.Server.Implementations/Data/ManagedConnection.cs
+++ b/Emby.Server.Implementations/Data/ManagedConnection.cs
@@ -7,7 +7,7 @@ using SQLitePCL.pretty;
 
 namespace Emby.Server.Implementations.Data
 {
-    public class ManagedConnection : IDisposable
+    public sealed class ManagedConnection : IDisposable
     {
         private readonly SemaphoreSlim _writeLock;
 
diff --git a/Emby.Server.Implementations/IO/FileRefresher.cs b/Emby.Server.Implementations/IO/FileRefresher.cs
index 47a83d77c..e62361c1e 100644
--- a/Emby.Server.Implementations/IO/FileRefresher.cs
+++ b/Emby.Server.Implementations/IO/FileRefresher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;
@@ -14,7 +12,7 @@ using Microsoft.Extensions.Logging;
 
 namespace Emby.Server.Implementations.IO
 {
-    public class FileRefresher : IDisposable
+    public sealed class FileRefresher : IDisposable
     {
         private readonly ILogger _logger;
         private readonly ILibraryManager _libraryManager;
@@ -22,7 +20,7 @@ namespace Emby.Server.Implementations.IO
 
         private readonly List<string> _affectedPaths = new List<string>();
         private readonly object _timerLock = new object();
-        private Timer _timer;
+        private Timer? _timer;
         private bool _disposed;
 
         public FileRefresher(string path, IServerConfigurationManager configurationManager, ILibraryManager libraryManager, ILogger logger)
@@ -36,7 +34,7 @@ namespace Emby.Server.Implementations.IO
             AddPath(path);
         }
 
-        public event EventHandler<EventArgs> Completed;
+        public event EventHandler<EventArgs>? Completed;
 
         public string Path { get; private set; }
 
@@ -111,7 +109,7 @@ namespace Emby.Server.Implementations.IO
             RestartTimer();
         }
 
-        private void OnTimerCallback(object state)
+        private void OnTimerCallback(object? state)
         {
             List<string> paths;
 
@@ -127,7 +125,7 @@ namespace Emby.Server.Implementations.IO
 
             try
             {
-                ProcessPathChanges(paths.ToList());
+                ProcessPathChanges(paths);
             }
             catch (Exception ex)
             {
@@ -137,12 +135,12 @@ namespace Emby.Server.Implementations.IO
 
         private void ProcessPathChanges(List<string> paths)
         {
-            var itemsToRefresh = paths
+            IEnumerable<BaseItem> itemsToRefresh = paths
                 .Distinct(StringComparer.OrdinalIgnoreCase)
                 .Select(GetAffectedBaseItem)
                 .Where(item => item != null)
-                .GroupBy(x => x.Id)
-                .Select(x => x.First());
+                .GroupBy(x => x!.Id) // Removed null values in the previous .Where()
+                .Select(x => x.First())!;
 
             foreach (var item in itemsToRefresh)
             {
@@ -176,15 +174,15 @@ namespace Emby.Server.Implementations.IO
         /// </summary>
         /// <param name="path">The path.</param>
         /// <returns>BaseItem.</returns>
-        private BaseItem GetAffectedBaseItem(string path)
+        private BaseItem? GetAffectedBaseItem(string path)
         {
-            BaseItem item = null;
+            BaseItem? item = null;
 
             while (item == null && !string.IsNullOrEmpty(path))
             {
                 item = _libraryManager.FindByPath(path, null);
 
-                path = System.IO.Path.GetDirectoryName(path);
+                path = System.IO.Path.GetDirectoryName(path) ?? string.Empty;
             }
 
             if (item != null)
diff --git a/Emby.Server.Implementations/IO/LibraryMonitor.cs b/Emby.Server.Implementations/IO/LibraryMonitor.cs
index b525f5a2f..9fcc7fe59 100644
--- a/Emby.Server.Implementations/IO/LibraryMonitor.cs
+++ b/Emby.Server.Implementations/IO/LibraryMonitor.cs
@@ -449,12 +449,12 @@ namespace Emby.Server.Implementations.IO
                 }
 
                 var newRefresher = new FileRefresher(path, _configurationManager, _libraryManager, _logger);
-                newRefresher.Completed += NewRefresher_Completed;
+                newRefresher.Completed += OnNewRefresherCompleted;
                 _activeRefreshers.Add(newRefresher);
             }
         }
 
-        private void NewRefresher_Completed(object sender, EventArgs e)
+        private void OnNewRefresherCompleted(object sender, EventArgs e)
         {
             var refresher = (FileRefresher)sender;
             DisposeRefresher(refresher);
@@ -481,6 +481,7 @@ namespace Emby.Server.Implementations.IO
         {
             lock (_activeRefreshers)
             {
+                refresher.Completed -= OnNewRefresherCompleted;
                 refresher.Dispose();
                 _activeRefreshers.Remove(refresher);
             }
@@ -492,6 +493,7 @@ namespace Emby.Server.Implementations.IO
             {
                 foreach (var refresher in _activeRefreshers.ToList())
                 {
+                    refresher.Completed -= OnNewRefresherCompleted;
                     refresher.Dispose();
                 }
 
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
index 5726d7158..a88a1fe84 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
@@ -187,7 +187,7 @@ namespace Emby.Server.Implementations.LiveTv.EmbyTV
                 CultureInfo.InvariantCulture,
                 "-i \"{0}\" {2} -map_metadata -1 -threads {6} {3}{4}{5} -y \"{1}\"",
                 inputTempFile,
-                targetFile.Replace("\"", "\\\""), // Escape quotes in filename
+                targetFile.Replace("\"", "\\\"", StringComparison.Ordinal), // Escape quotes in filename
                 videoArgs,
                 GetAudioArgs(mediaSource),
                 subtitleArgs,
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
index f9d151a81..9ab4cc628 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
@@ -51,7 +51,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
         public async Task<bool> CheckTunerAvailability(IPAddress remoteIp, int tuner, CancellationToken cancellationToken)
         {
             using var client = new TcpClient();
-            client.Connect(remoteIp, HdHomeRunPort);
+            await client.ConnectAsync(remoteIp, HdHomeRunPort).ConfigureAwait(false);
 
             using var stream = client.GetStream();
             return await CheckTunerAvailability(stream, tuner, cancellationToken).ConfigureAwait(false);
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
index 506ef5548..708ff52d7 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
@@ -283,7 +283,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             // #EXTINF:0,84.0 - VOX Schweiz
             if (!string.IsNullOrWhiteSpace(nameInExtInf))
             {
-                var numberIndex = nameInExtInf.IndexOf(' ');
+                var numberIndex = nameInExtInf.IndexOf(' ', StringComparison.Ordinal);
                 if (numberIndex > 0)
                 {
                     var numberPart = nameInExtInf.Substring(0, numberIndex).Trim(new[] { ' ', '.' });
diff --git a/Emby.Server.Implementations/Playlists/PlaylistManager.cs b/Emby.Server.Implementations/Playlists/PlaylistManager.cs
index b07798fa4..9481e26f7 100644
--- a/Emby.Server.Implementations/Playlists/PlaylistManager.cs
+++ b/Emby.Server.Implementations/Playlists/PlaylistManager.cs
@@ -527,7 +527,7 @@ namespace Emby.Server.Implementations.Playlists
             var relativeUri = folderUri.MakeRelativeUri(fileAbsoluteUri);
             string relativePath = Uri.UnescapeDataString(relativeUri.ToString());
 
-            if (fileAbsoluteUri.Scheme.Equals("file", StringComparison.CurrentCultureIgnoreCase))
+            if (fileAbsoluteUri.Scheme.Equals("file", StringComparison.OrdinalIgnoreCase))
             {
                 relativePath = relativePath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
             }
diff --git a/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs b/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
index bd1966623..67a9fbd3b 100644
--- a/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
+++ b/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
@@ -26,7 +26,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.Int32.</returns>
         public int Compare(BaseItem? x, BaseItem? y)
         {
-            return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(GetValue(x), GetValue(y), StringComparison.OrdinalIgnoreCase);
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/Sorting/AlbumComparer.cs b/Emby.Server.Implementations/Sorting/AlbumComparer.cs
index fe7dc84cb..4d09dda84 100644
--- a/Emby.Server.Implementations/Sorting/AlbumComparer.cs
+++ b/Emby.Server.Implementations/Sorting/AlbumComparer.cs
@@ -25,7 +25,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.Int32.</returns>
         public int Compare(BaseItem? x, BaseItem? y)
         {
-            return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(GetValue(x), GetValue(y), StringComparison.OrdinalIgnoreCase);
         }
 
         /// <summary>
@@ -35,9 +35,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.String.</returns>
         private static string? GetValue(BaseItem? x)
         {
-            var audio = x as Audio;
-
-            return audio == null ? string.Empty : audio.Album;
+            return x is Audio audio ? audio.Album : string.Empty;
         }
     }
 }
diff --git a/Emby.Server.Implementations/Sorting/ArtistComparer.cs b/Emby.Server.Implementations/Sorting/ArtistComparer.cs
index 7b7ba5753..a8bb55e2b 100644
--- a/Emby.Server.Implementations/Sorting/ArtistComparer.cs
+++ b/Emby.Server.Implementations/Sorting/ArtistComparer.cs
@@ -17,7 +17,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <inheritdoc />
         public int Compare(BaseItem? x, BaseItem? y)
         {
-            return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(GetValue(x), GetValue(y), StringComparison.OrdinalIgnoreCase);
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/Sorting/NameComparer.cs b/Emby.Server.Implementations/Sorting/NameComparer.cs
index 8f87717f4..c2875eeb9 100644
--- a/Emby.Server.Implementations/Sorting/NameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/NameComparer.cs
@@ -34,7 +34,7 @@ namespace Emby.Server.Implementations.Sorting
                 throw new ArgumentNullException(nameof(y));
             }
 
-            return string.Compare(x.Name, y.Name, StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(x.Name, y.Name, StringComparison.OrdinalIgnoreCase);
         }
     }
 }
diff --git a/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs b/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
index 4123a59f8..0bd9600b9 100644
--- a/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
@@ -25,7 +25,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.Int32.</returns>
         public int Compare(BaseItem x, BaseItem y)
         {
-            return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(GetValue(x), GetValue(y), StringComparison.OrdinalIgnoreCase);
         }
 
         private static string GetValue(BaseItem item)
diff --git a/Emby.Server.Implementations/Sorting/SortNameComparer.cs b/Emby.Server.Implementations/Sorting/SortNameComparer.cs
index fb97a0349..79be9a89a 100644
--- a/Emby.Server.Implementations/Sorting/SortNameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/SortNameComparer.cs
@@ -36,7 +36,7 @@ namespace Emby.Server.Implementations.Sorting
                 throw new ArgumentNullException(nameof(y));
             }
 
-            return string.Compare(x.SortName, y.SortName, StringComparison.CurrentCultureIgnoreCase);
+            return string.Compare(x.SortName, y.SortName, StringComparison.OrdinalIgnoreCase);
         }
     }
 }
diff --git a/RSSDP/HttpParserBase.cs b/RSSDP/HttpParserBase.cs
index c56249523..6b6c13d99 100644
--- a/RSSDP/HttpParserBase.cs
+++ b/RSSDP/HttpParserBase.cs
@@ -82,7 +82,7 @@ namespace Rssdp.Infrastructure
                 throw new ArgumentNullException(nameof(versionData));
             }
 
-            var versionSeparatorIndex = versionData.IndexOf('/');
+            var versionSeparatorIndex = versionData.IndexOf('/', StringComparison.Ordinal);
             if (versionSeparatorIndex <= 0 || versionSeparatorIndex == versionData.Length)
             {
                 throw new ArgumentException("request header line is invalid. Http Version not supplied or incorrect format.", nameof(versionData));
@@ -101,7 +101,7 @@ namespace Rssdp.Infrastructure
         {
             // Header format is
             // name: value
-            var headerKeySeparatorIndex = line.IndexOf(":", StringComparison.OrdinalIgnoreCase);
+            var headerKeySeparatorIndex = line.IndexOf(':', StringComparison.Ordinal);
             var headerName = line.Substring(0, headerKeySeparatorIndex).Trim();
             var headerValue = line.Substring(headerKeySeparatorIndex + 1).Trim();
 
@@ -172,7 +172,7 @@ namespace Rssdp.Infrastructure
             else
             {
                 var segments = headerValue.Split(SeparatorCharacters);
-                if (headerValue.Contains('"'))
+                if (headerValue.Contains('"', StringComparison.Ordinal))
                 {
                     for (int segmentIndex = 0; segmentIndex < segments.Length; segmentIndex++)
                     {
diff --git a/jellyfin.ruleset b/jellyfin.ruleset
index e14c1c427..469f61021 100644
--- a/jellyfin.ruleset
+++ b/jellyfin.ruleset
@@ -38,8 +38,14 @@
   </Rules>
 
   <Rules AnalyzerId="Microsoft.CodeAnalysis.NetAnalyzers" RuleNamespace="Microsoft.Design">
+    <!-- error on CA1063: Implement IDisposable correctly -->
+    <Rule Id="CA1063" Action="Error" />
     <!-- error on CA1305: Specify IFormatProvider -->
     <Rule Id="CA1305" Action="Error" />
+    <!-- error on CA1307: Specify StringComparison for clarity -->
+    <Rule Id="CA1307" Action="Error" />
+    <!-- error on CA1309: Use ordinal StringComparison -->
+    <Rule Id="CA1309" Action="Error" />
     <!-- error on CA1725: Parameter names should match base declaration -->
     <Rule Id="CA1725" Action="Error" />
     <!-- error on CA1725: Call async methods when in an async method -->