Issue with reCAPTCHA

Had no issues with using reCAPTCHA on the forms on my other website. But with this particular one, each time I am getting this error message: "Unable to send your message. Please fix errors then try again." when I hit the submit button the first time. After closing the error message window, I press on submit and the message goes through.

Any help, suggestion would be much appreciated.

Here's a link where you can try the form to see what I am talking about. https://www.airwashsystems.com/MobileAir-Desktop-Air-Purifier.html

Thank you very much in advance for your help.

Pablo