Visitor Split-Session Not Working Properly

Hello,

Our application currently works as follows (using the Chat API (JavaScript)):

1. User starts a LP chat on the client's web site
2. User engages a virtual agent
3. The client passes the session id from #1 to the virtual agent through a JS variable
4. If and when a user starts a LP chat through the virtual agent,
   1. The virtual agent passes session ID from step #1 to LP
   2. LP merges the chats from session #1 and session #4 into a single chat session (instead of creating a new session with session #4)

However, in the agent console two sessions are created for this user instead of the two sessions being merged.  We have confirmed with a LP program manager (who advised us to ask this question here) that the session ID received in step #1 is correct and that it is being passed to #3 correctly.  We are unsure though if we are passing it correctly in the call to request the chat in step #4.

We are calling this to connect:

https://api.liveperson.net/api/account/xxxxxxxx?v=2

To request a chat we are calling:

https://sales.liveperson.net/api/account/xxxxxxxx/chat/request?v=2

We are passing this JSON in the body of the request:

{

    "request": {

        "skill": "...",

        "visitorIp": "...",

        "chatReferrer": "...",

        "visitorSessionId": "lp_sessionid",

        "preChatLines": {

            "line": "..."

        },

        "customVariables": [

            {

                "name": "SCI",

                "value": "v"

            },

            {

                "name": "sessionId",

                "value": "lp_sessionid"

            }

        ]

    }

}

lp_sessionid is the session ID that is given to us in step #3.

Thanks for any help!