Why xdt:Transform (web.config) has no effect in VS 2017 Community?

Hello 

I migrate my VS 2010 project to VS 2017

In Web.config will be changed SQL-Server-connection String in accordance to live or testsystem.

it achived with following command in Web.Release.config

<addname="myConnectionString"connectionString="Data Source=MyServer;Initial Catalog=MyDatabase;Integrated Security=True"xdt:Transform="SetAttributes"xdt:Locator="Match(name)"/>

But in VS 2017 it does not work:

- after deployment on live-system is the connection string in Release.Web.Config not overwritten and still reference to development-system.

Why it is so,  and how can achive I this goal?

Thanks