Hello,
We were not able to replicate the issue with the link provided above. Yesterday we successfully sent a test submissions. To help narrow down the cause of the issue I would suggest first disabling the Contact Form 7 – ReCaptcha v2 plugin and see if that solves the issue. If the form submits with out plugin disabled then we will need further information such as:
– Installed plugins
– What the active theme is
With the above information we may be able to replicate the issue. Additionally, you may want to install the WordPress Health Check Plugin which will allow you to safely ( and for your logged in user ) disable plugins until you come across the plugin causing the issue. The Health Check Plugin also allows you to switch themes to the default theme ( again, just for your logged in user ) to see if it’s possibly a theme conflict.
You may want to test this on a different computer or a different browser to make sure it’s not an browser extension issue. Any further information you feel will help us replicate the issue could be appreciated!