Quick Look Preview of html files not working after iOS 13 upgrade in iPad After updating to iOS X 13, I can no longer use Quick Look on HTML files available in mail – I just get a blank preview window or enable javascript window, and the issue persists through a reboot. But all other files types work fine.

Is there a cache I can clear or something else I can try to get this working again?
Apple has disabled JavaScript in Quick Look for security/privacy reasons (this was used to track users previewing local files by pinging remote servers). 

If you have your own app, use a WKWebView if you need JavaScript execution. If you are sending HTML content with JavaScript via email, send a link to a remote server instead. With a link people know they are contacting a remote server.