Sharing Session Between 2 Web Application
The Session State server is not running for that purpose. It is designed to provide a separation of state from the worker process, and can thus be used for things like web gardens/farms and for some degree (albeit lightweight) of fault tolerance.
Each application receives its own store in the state server, and state cannot be shared between applications this way. The only thing wrong with the code is that you are attempting to use the state server for something that it's not designed to do.
If you want to share data between applications, I'd recommend that you use a database.