Some users are not able to submit the form

I set up a survey using JF and initially enabled form editing. Later I turned it off because it's a quick and easy form. 

That said, I'm getting reports that multiple people from the same household are not able to submit the form, even though they are using different email addresses... 

Am I missing something?

Greetings and thank you for your message.

To help you fully, we will need some additional information from you.

Can you please let us know do they get any error messages when they try to submit the form? Are there any errors on the form? Can they get to the Thank you page?

Feel free to attach any screenshots of the form you think might help us. You can click here to see how to post images.

Thank you for your cooperation.