upon submitting the form, mail is sent fine, however if you have this plugin Contact Form 7 – Success Page Redirects
it doesn’t perform redirect, or to be precise, in Inspector 302 is registered, email is successfully sent, but doesn’t load the redirected URL. No warnings, no errors. Was able to reproduce the issue with only 3 plugins installed, Latest Contact Form 7, latest available “Success page redirect” and latest of your plugin.
Managed to get it to work by disabling Redirect plugin and manually adding settings to: on_sent_ok: “location = ‘http://example.com/’;”, but I’m wondering what is causing the error.