Steps to reproduce:

1. send the following payload to the api

    {
       "jsonrpc": "2.0",
        "method": "proxy.update",
        "params": {     
          "proxyid": "33520",
          "hosts": [ "13465"]
       },
     "id": 1,
     "auth": "{{auth}}"
    }
   

Result:

{
    "jsonrpc": "2.0",
    "error": {
        "code": -32602,
        "message": "Invalid params.",
        "data": "Invalid parameter \"/1/hosts/1\": an array is expected."
    },
    "id": 1
}