Collection of records parameter into a sub process

Hi all,

I am running a process to deserialise a JSON string from a webhook and pass the results (an email address and a state) into a sub process.

The deserialisation step works as I can see the results which have been passed into the collection of records parameter in the process log (only 1 in this sample):

Parent process
                {
            "Parameter": "Bouncebacks",
            "Value": {
                "Before execution": [
                    {
                        "email": "billy.bob@river.com",
                        "__state__": "bounced"
                    }
                ],
                "After execution": [
                    {
                        "email": "billy.bob@river.com",
                        "__state__": "bounced"
                    }
                ]
            }
        }

  I pass this collection into a sub-process but the values don't appear to pass in correctly:

//Sub process
        "Process parameters": [
        {
            "Parameter": "Email",
            "Value": {
                "Before execution": null,
                "After execution": null
            }
        },
        {
            "Parameter": "State",
            "Value": {
                "Before execution": null,
                "After execution": null
            }
        }
    ]      

  I cannot figure out why not. Any ideas?