Shell run in endless at Web application

I asked about run command and UI same time.
https://forum.xojo.com/59187-ui-freeze-while-thread-running
This question is solved and very work well in Desktop application.

But, shell run in endless at web application.

I put PushButton1,Label1,Shell1.

Button1 .Action :

Shell1.ExecuteMode = Shell.ExecuteModes.Asynchronous Shell1.TimeOut = -1 // for Windows Shell1.Execute("start /w notepad %USERPROFILE%\\Documents\\test.txt && type %USERPROFILE%\\Documents\\test.txt")

Shell1.DataAvailable :

In the Desktop app, notepad runs only one.
But in the web app, notepad re-open when I close notepad. Notepad endless run.

Why?

I write miss! Above code is good. But, My code on application is miss.
Web application work well.
Sorry!