try to fix bug

server/src/UdpServer.cs

@@ -92,7 +92,7 @@ public class UDPServer
         {
             Console.WriteLine(e.ToString());
             throw new ArgumentException(
-                $"Not currect port num: {port}",
+                $"Failed to set up server with this port: {port}",
                 nameof(port)
                 );
         }
@@ -143,7 +143,7 @@ public class UDPServer
         }
         else
         {
-            return Optional.Some((UDPData)data);
+            return Optional.Some((UDPData)data.DeepClone());
         }
     }
 
@@ -196,7 +196,7 @@ public class UDPServer
         }
         else
         {
-            return Optional.Some((UDPData)data);
+            return Optional.Some((UDPData)data.DeepClone());
         }
     }