In my case the issue is autoptimize with the following option checked:
Aggregate JS-files? (Aggregate all linked JS-files to have them loaded non-render blocking? If this option is off, the individual JS-files will remain in place but will be minified.)
I guess any plugin optimizing the JS files maybe affected? This article may help:
https://blog.futtta.be/2021/02/25/contact-form-7-update-breaks-autoptimize-js-optimization-workaround/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+futtta_autoptimize+%28Frank+Goossens%27+blog++%C2%BB+autoptimize%29
Found the issue. The plugin affecting contact form 7 is Autoptimize.
Same issue, form is sent but no confirmation message on the page and submit button spinning. Used to work fine with the same plugins I have for years…
A work around this issue is using recaptcha v2 with the following plugin for integration:
ReCaptcha v2 for Contact Form 7
With the above combo the contact form works fine.
