«Argument 1 passed to Ebizmarts_MailChimp_Helper_Data::isEcomSyncDataEnabled() must be of the type int, null given»

OpenMage: 19.5.2
PHP: 7.4.33
IP Address: 172.69.115.130
Referer: https://www.thehcginstitute.com/store/index.php/admin/sales_order_create/index/customer_id/13431/
Request Method: POST
URL: https://www.thehcginstitute.com/store/index.php/admin/sales_order_create/save/
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36
Post: 
{
    "coupon_code": "",
    "entity_id": "",
    "form_key": "zyNNGhhvFIbyOLDI",
    "in_products": "",
    "item": {
        "86483": {
            "action": "",
            "qty": "2",
            "use_discount": "1"
        }
    },
    "limit": "20",
    "name": "",
    "order": {
        "account": {
            "dob": "8/31/1971",
            "email": "<…>@gmail.com",
            "gender": "2",
            "visitorid": ""
        },
        "billing_address": {
            "city": "Kenmore",
            "company": "",
            "country_id": "US",
            "customer_address_id": "9429",
            "fax": "",
            "firstname": "Heide",
            "lastname": "<…>",
            "middlename": "",
            "postcode": "98028",
            "prefix": "",
            "region": "",
            "region_id": "62",
            "street": [
                "<…>",
                ""
            ],
            "suffix": "",
            "telephone": "<…>",
            "vat_id": ""
        },
        "comment": {
            "customer_note": ""
        },
        "currency": "USD",
        "send_confirmation": "1",
        "shipping_method": "flatrate2_flatrate2"
    },
    "page": "1",
    "payment": {
        "cc_cid": "<…>",
        "cc_exp_month": "6",
        "cc_exp_year": "2027",
        "cc_number": "<…>",
        "cc_owner": "<…>",
        "cc_type": "AE",
        "method": "amexsavedcc"
    },
    "price": {
        "from": "",
        "to": ""
    },
    "shipping_as_billing": "1",
    "sku": ""
}
File: app/code/community/Ebizmarts/MailChimp/Helper/Data.php
Line: 807
************************************
[E_ERROR] Uncaught TypeError: Argument 1 passed to Ebizmarts_MailChimp_Helper_Data::isEcomSyncDataEnabled() must be of the type int, null given, called in app/code/community/Ebizmarts/MailChimp/Model/Observer.php on line 368 and defined in app/code/community/Ebizmarts/MailChimp/Helper/Data.php:807
Stack trace:
#0 app/code/community/Ebizmarts/MailChimp/Model/Observer.php(368): Ebizmarts_MailChimp_Helper_Data->isEcomSyncDataEnabled(NULL)
#1 app/code/core/Mage/Core/Model/App.php(1399): Ebizmarts_MailChimp_Model_Observer->customerSaveAfter(Object(Varien_Event_Observer))
#2 app/code/core/Mage/Core/Model/App.php(1371): Mage_Core_Model_App->_callObserverMethod(Object(Ebizmarts_MailChimp_Model_Observer), 'customerSaveAft...', Object(Varien_Event_Observer), 'mailchimp_save_...')
#3 app/Mage.php(508): Mage_Core_Model
thehcginstitute-com / m1

«Argument 1 passed to Ebizmarts_MailChimp_Helper_Data::isEcomSyncDataEnabled() must be of the type int, null given» #577
