Problem with Windows Parallels Client Connection via Proxy Server

Hi All,
I have a problem with the connection to our Parallels Server.
In the network of the client, i have to use a proxy to connect https to internet.

After the configuration, i get a first connection, and i can see the app Icon.
But if i start the app, i get an connection error, and it tries to connect directly to the parallels server.
after a restart of the parallels client, it didn't connect at all (even not app icon)
Any ideas?
Best Regards