Tom PRO said 12 months ago on Building a Questionnaire :

Having an annoying issue on this one - it looks like adding multiple answers to a question when creating a new questionnaire causes only the last answer to be accepted (only shows one in the dev log in the request too),  but it works fine when editing an existing questionnaire. It looks like 'Add answer' is creating multiple of the same block of HTML when creating a new questionnaire, i.e. 

var content = this.templateTarget.innerHTML.replace(/TEMPLATE_RECORD/g, new Date().getTime())

in nested_form_controller.js appears not to be working correctly (I think) - even when directly copy/pasting from the code blocks above, but only for new questionnaires. Any ideas?