Empty html downloaded automatically

I’ve asked to chatgpt:

“If I quickly exit one of my posts with free online game iframes, I download a blank html. Could any protection cause this? HTTPS, Turnstile, firewall, something else?”

And it’s reply are:

“The issue may be due to various levels of protection or server configurations, especially if the site uses advanced security mechanisms. Here are some possible causes:
1. HTTPS and Mixed Content

If the main page is served over HTTPS but the iframe tries to load content over HTTP (without HTTPS), modern browsers block the loading to prevent mixed content, potentially resulting in a blank page in the iframe.
Make sure all content is served over HTTPS.

2. Firewalls and Web Application Firewalls (WAFs)

Some firewalls or Web Application Firewalls (WAFs) may block resource loads if they detect suspicious traffic or policy violations. This can include iframes from third-party domains or multiple requests in rapid succession, which are considered bots or threats.
Check your firewall settings to see if there are any rules that might be interfering.

3. Turnstile or Other CAPTCHA Systems

If your site uses a system like Cloudflare’s Turnstile (or Google’s reCAPTCHA) to verify that the user is human, it may block iframes from loading based on the behavior detected. For example, if there is a session switch or if the user interacts with the site in a way that is considered abnormal, the iframe content may not load.
Consider implementing less restrictive verification rules for loading specific content into the iframe.

4. Security Headers (CSP and X-Frame-Options)

The Content-Security-Policy (CSP) header can limit which origins are allowed to load content into iframes. If the host site has a CSP that does not include the origin of the iframe, the iframe will be blocked.
The X-Frame-Options header can be configured to prohibit loading the site in an iframe on different domains.
Check these headers to make sure they allow games to load in the correct context.

5. Timeouts or Temporary Network Errors

If you exit the post very quickly, there may be a timeout or cancellation of the request to the server, which may send an empty HTML response as a fallback.
Some servers and browsers may do this to save resources. Check your server logs for broken responses.

6. JavaScript Restrictions

Some security libraries or JavaScript configurations may erase or alter the contents of an iframe if they do not complete their execution.
If your game depends on JavaScript to load and is interrupted, you may see a blank page.

Tips

Review your server logs and use your browser’s developer tools to see any error messages, restrictions, or blocks on consoles.
Check any custom rules in your security systems and verify that URLs requested by iframes are included in the allow lists for both CSPs and firewalls or WAFs.”

Unfortunately the host refuses to help, even give advice. I don’t want Google to download too fast and only see the empty html. That would explain why fixes are rare, and it sees many low-value posts.

I’ve been doing a lot of fixes lately, but if I could figure out how to fix or test the empty html error better, I might try to fix it.