Unable to submit – error appears

Our clients are unable to submit their forms via: http://www.ledbetterinc.com/vip-check-in – which works great on Safari and Internet Explorer, but not Google Chrome and Firefox.

I recently did this list according to documents and FAQ from CF7:
– Updated “Email” in “Settings” of WordPress.
– Plugged in SMTP because we use Gmail account to receive clients’ forms.
– Configured, but received false instead of true – unable to detect bugs, although everything else is up to date and aligned with Contact Form 7.
– The Catchpa plug-in is installed as needed, aligned with Akismet key to prevent spam.

Now, I am confused with what I can do to fix the contact form as it is unsuccessful after hours of trying to find what was wrong with it, especially with Google Chrome & Firefox.

Talk soon, and thanks in advance –
Josh.

https://ww.wp.xz.cn/plugins/contact-form-7/