Javascript Help needed

Hi All,

I have this issue which is not allowing me to use my Email Optin form. When you enter details and submit it just goes to the top of the page. I'm using Divi Builder and I only seem to have this issue with Firefox.

above is a screenshot of what's been diagnosed at the moment, but I'm unsure how to find the culprit to fix or remove.

Any help will be greatly appriciated.

Kind Regards,

Dwayne