Captcha not working on mobile

Hello,

I am using the FS Contact Form on https://riverpodcast.com/contact-us/ and it works fine on desktop but when I try on mobile (specifically, iPhone), it continually says the “The CAPTCHA was incorrect. Try again.” I’ve had others also try on their smartphones with the same result.

Thank you for your assistance!

https://www.ads-software.com/plugins/si-contact-form/