Once the tracking class was added we also experienced trouble with the form’s submission process. Essentially the form submission button had to be clicked twice for the submit process to fire.
To fix the submission error we had to rename the form’s submit input name attribute to anything other than ‘submit’. Having the submit button’s name attribute as ‘submit’ causes our tracking system to break.
This is the code we told our client to add into their theme’s global js file to add the tracking class to webinar registration forms and to rename the submit button name attribute to something benign: