Webform Error message - can anyone help?

Hello ,

We use smartsheet webforms for daily reports for some of our volunteer workers..this works fine when the forms are filled out on a computer, however when filled out in our school app and submitted, they get the attached error message saying "this form is not found".  Despite this, we still receive the reports into the smartsheet, but it is stopping people from filling them out since they think they are not being received. 

Any ideas why this might be? or how to disable this message from showing up?

Hoping theres an easy fix!

Thanks.