Required question not work on my form

I have a form at the URL listed below with more than one required question.  When testing the form, if I don't answer the second required question, I don't get a missing response warning and the form just hangs up and doesn't submit.

Please provide any help.

Thanks.

So far I could not replicate the issue described when I test using your form URL. The required validation properly triggers and I cannot submit the form if I leave a mandatory question empty/blank.

May I ask if you have instead published the form on a website? Perhaps issue happens in the published form only. If you can share to us the URL of your website, we will also test the form used.

Let us know if issue persist.