Zoho Webform suddenly not working on our website

Zoho Webform suddenly not working on our website

Hi,

I have 20 different web forms on our website to capture leads, we create the webform via developer space > webforms in Zoho CRM. I copy the Source code and input this into our wordpress site. For some reason, these forms have stopped working. If a user enters their information into the form and hits submit the page does not redirect to the thank you landing page, it just refreshes the existing page. the leads are not recorded in zoho crm. 

Any idea why these forms would suddenly stop working?