Create Webhook API returns 200 response with empty body

Shopify Apps
1

We have a custom app and Admin API access token with the write and read orders permissions.

Attempting to create a webhook via API for the orders/create topic. Have tried via Postman and cURL. Double-checked all params.

Request: POST https://[redacted]/admin/api/2024-01/webhooks.json

Request body:

{
    "webhook": {
        "topic": "orders/create",
        "address": "[redacted]",
        "format": "json"
    }
}

The response is always 200 HTTP code with an empty webhooks list:

{
    "webhooks": []
}

Even if I modify the request to have a broken request body, I still get 200 response with empty webhooks array.

I found this question: https://community.shopify.com/post/2345878. Which had the same issue in December 2023, and it has no responses.

Can anybody weigh in on what might be going wrong?