diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/Ipc/TcpFrameServer.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/Ipc/TcpFrameServer.cs
index 78161047..a253c9f6 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/Ipc/TcpFrameServer.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/Ipc/TcpFrameServer.cs
@@ -81,6 +81,13 @@ public sealed class TcpFrameServer : IDisposable
 
         using (client)
         {
+            // net48's NetworkStream.ReadAsync ignores the CancellationToken, so cancelling the
+            // token alone cannot unblock the frame loop when it's parked reading an idle client —
+            // only closing the socket does. Register the cancel to Close() the active client so
+            // RunAsync actually unwinds on shutdown (mirrors the listener.Stop() above that
+            // unblocks a parked AcceptTcpClientAsync). Without this, RunAsync().GetAwaiter() in
+            // Program.Main never returns on Ctrl-C/service-stop while a connection is open.
+            using var clientReg = linked.Token.Register(() => { try { client.Close(); } catch { /* ignore */ } });
             client.NoDelay = true;
             Stream stream = client.GetStream();
             SslStream? ssl = null;
@@ -129,6 +136,14 @@ public sealed class TcpFrameServer : IDisposable
                     await handler.HandleAsync(frame.Value.Kind, frame.Value.Body, writer, linked.Token).ConfigureAwait(false);
                 }
             }
+            catch (Exception) when (linked.Token.IsCancellationRequested)
+            {
+                // The clientReg cancel callback closed the socket mid-read/handshake (net48 read
+                // doesn't observe the token); surface it as cancellation so RunAsync's
+                // OperationCanceledException path unwinds cleanly instead of logging a connection
+                // failure and counting it toward MaxConsecutiveFailures.
+                throw new OperationCanceledException(linked.Token);
+            }
             finally { ssl?.Dispose(); }
         }
     }