fulfillmentCreateV2 GQL request returns "INTERNAL_SERVER_ERROR"

18 3 4

So I'm making a GQL request to fulfill an order, using the fulfillmentCreatev2 Mutation. Here's my request :

        mutation {
            fulfillmentCreateV2(fulfillment: 
                {
                    lineItemsByFulfillmentOrder:
                    {
                        fulfillmentOrderId:"gid://shopify/FulfillmentOrder/4035491463266"
                    },   
        		     notifyCustomer:true
                }
             ) {
            userErrors {
                field
                message
            }
         }
    }

Here's the server's response:

{
    "errors": [
        {
            "message": "Internal error. Looks like something went wrong on our end.\nRequest ID: a22b377b-d919-4e9d-aeca-36f67bc4f024 (include this in support requests).",
            "extensions": {
                "code": "INTERNAL_SERVER_ERROR",
                "requestId": "a22b377b-d919-4e9d-aeca-36f67bc4f024"
            }
        }
    ]
}

I'm contacting support as well, but if anyone knows of any solution from my end, it would be greatly appreciated!