I put in a ticket yesterday with VFB. They replied:
“Thank you for using Visual Form Builder Pro! We are sorry for any trouble you might be experiencing and we are happy to assist you. There is an issue related to where javascript is disabled allowing for required field/reCaptcha to be bypassed. The Developer is aware of this happening. As of now, I am not sure of a time-frame of when the issue will be addressed, However I do suggest keeping an eye out for future updates and their change logs via email notice. I always suggest placing the Hidden Field with the option to collect the user’s IP Address to see if there is any correlation.”
Basically we have to wait until the fix is implemented.