Body is unusable: Body has already been read error

[kyllerss]

I have fairly straight-forward code on one particular endpoint called /push_notifications.json that has the following code:

export async function POST(event: RequestEvent) {

    let user_account_uuid = (event.locals.session)?.user_account?.uuid;
    if (user_account_uuid === undefined)  {
        return json({success: false});
    }

    const form_data = await event.request.formData(); // <- many errors here!
    
    ... // shenanigans

    return json({success: true});
}

I am getting a very high number of errors stating that the body has already been consumed:

Body is unusable: Body has already been read

I can't reproduce this in local Dev environment, this is only occurring in Production. The app is deployed on Vercel. I am wondering if this has something to do with middle-ware being inserted into the stack by Vercel.

Has anyone run into this problem? Is there is anything I can do to alleviate the issue?