Why Can't I Retrieve Submitted Instances from a Simple Web Form in the Developer Environment?

Hello everyone,

I have created a simple Web Form with only two fields, FirstName and LastName, using my DocuSign developer account. I've activated the form link and submitted data multiple times, including some submissions in Incognito mode with different names. However, when I send a GET request to retrieve all instances via the following API route:

/api/webforms/v1.1/accounts/{accountId}/forms/{formId}/instances

I receive an empty list ([]).

{
    "items": []
}

I’m unable to find any of the submitted form data.

Could anyone explain why this is happening? Is it expected that form submissions don't appear in the developer environment, or should I be able to retrieve submitted data even in dev mode? Or perhaps are there restrictions on the Web Forms API in the developer environment that only allow access in production mode?

For context, I am using JWT Grant for authentication and have admin access to my developer account. I’ve followed the instructions in the DocuSign documentation:

Web Forms API Reference - List Instances

Any insights or suggestions on how to retrieve the submitted instances would be greatly appreciated!

Thanks in advance!