I have a couple of forms on my website and both are hanging up suddenly today when submitting forms. The form data does get saved and sent, but there is a spinning circle when pressing the submit circle and the website visitor is not redirected to the thank you page.
This seems to have resolved itself. The site is hosted by Siteground, so maybe there was a problem there, or some other general internet slow-down. The website visitors are now being redirected properly, although it is slow.
Sitegrounds optimizer is known to cause intermittent issues, including optimizing the ajax postback in such a way that the form scripts can’t parse the response, so it can’t complete the submission.
We generally recommend excluding pages that include forms from caching/optimization. See the following page for more details: