Email validator works on landing page, but data gets sent to Hubspot anyway

Hi everyone, I hope that someone will be able to provide some help. We’ve got landing pages with a multi-step (technically, multi-page) form. The form field on the last step includes email. We use email validation code to prevent generic email accounts from being used. The issue that we’re having is that while the email validator works in the landing page interface (if I use a gmail account, it will not let me submit the form, and returns an error message), the form data actually gets passed to Hubspot, which we’ve integrated with Unbounce. Has anyone run into this before? Any advice would be much appreciated!