'si connect' hangs when client is not connected to server

I am working on a script with PTC Integrity interactions. To be sure the IntegrityClient is running, I call 'si connect' first:

si connect --gui --hostname=someserver.domain.org --port=1234

1. In case the client is not running, it is started and the user is prompted for username and password => OK
2. In case the client is running, the command just returns => OK
3. When the client is running, but it is currently not connected - red exclamation mark next to 'user@server:port' in the status bar - then the command hangs infinitely => BAD

I also tried the command in batch mode, which I usually use to check if the client is running but prevent from starting if not, has the same behavior:

si connect --batch

When I go to the IntegrityClient window and get the connection up again, by just clicking to any sandbox member, the commands work properly again.

Is there an option for 'si connect' or another command, which I didn't see, to force the re-connection of the IntegrityClient without blocking the execution of a script?