HTTPS link in HTML Form being converted to HTTP with 443 port on load inside Iframe

Good afternoon everyone. I am working to embed reports in our application with the report service provider of Domo. I have created the following component.

import React from 'react';

const generateFormHtml = (actionUrl, embedToken) => (
    `
    <!DOCTYPE html>
    <html>
        <body>
            <form id="embedForm" action="${actionUrl}" method="post">
                <input type="hidden" name="embedToken" value="${embedToken}" />
            </form>
            <script>
                        document.getElementById("embedForm").submit();
            </script>
        </body>
    </html>
    `
);

const generateDataUri = (html) => `data:text/html;charset=utf-8,${encodeURI(html)}`;

const ReportEmbedder = ({ actionUrl, embedToken }) => {
    const htmlContent = generateFormHtml(actionUrl, embedToken);
    const formDataUri = generateDataUri(htmlContent);

    return (
        <iframe
            className="panel embed-panel"
            src={formDataUri}
            title="Embedded Form"
            allowtransparency="false"
        />
    );
};

export default ReportEmbedder;

That component is being called inside the main page inside the html

        /// actionUrl = 'https://public.domo.com/embed/pages/XXXXX'
        /// embedToken = 'full_length_embed_token'

            <div className="panel-container">
                    <ReportEmbedder
                            actionUrl={actionUrl}
                            embedToken={embedToken}
                        />
            </div>

My problem is that when the form renders, it seems to be converting the https url to http with a port associated.

HTTP ERROR 403 Access Denied
URI: http://public.domo.com:443/embed/pages/XXXXXX
STATUS: 403
MESSAGE: Access Denied

Does anyone have any idea how this could be happening or where to look? I have a feeling it is just a configuration issue that I have overlooked but I have yet to find it.

I have worked with debugging to ensure that the URI states https through the entire process. I have confirmed that in the generateDataUri step, the encoding is not over-riding the https setting. I have had a few other engineers peer review but they have been just as confused as myself.

I am expecting the https link to continue so that the iframe loads the report from the endpoint.