Hello Mig & Tan, We're sorry you're experiencing this issue with your form. We run a few tests and could not replicate the issue. It's possible that this is form specific. Please reach out to us through our support contact form at www.jotform.com/contact/ and provide your form link so we can troubleshoot it on our browser. Once we identify the issue, we'll be able to assist you moving forward. Thanks!

Hi, Disable Submit option is only available on the Card Form Layout. For the Classic Form Layout, it's best to use Show/Hide condition the Hide the Submit Button according to your IF rule. It would give you better result since the Submit Button is hidden in the form so it can't be easily manipulated. Example: link.jotform.com/bgKIjHa53q