Restsharp PropertyName serialization problem in version 108.0.1

I use RestSharp without any JsonSerializerOptions. After upgrading from 106.11.7 on .net5 to 108.0.1 on .net6:

before upgrade our request:

{
    "DATA": [
        {
            "WORK_ORDER_NO": "W123213",
            "COMPANY_CODE": "C423432",
            "VC_FLAG": "4",
            "INVOICE_COMPANY_CODE": "C423432"
        }
    ]
}

But after upgrade our request started to be generated like below:

{
    "data": [
        {
            "worK_ORDER_NO": "W123213",
            "companY_CODE": "C423432",
            "vC_FLAG": "4",
            "invoicE_COMPANY_CODE": "C423432"
        }
    ]
}