Form not for some customers

One of my clients reported 2 people not being able to use the for on his website, but I can't seem to duplicate any issue. 

Do you guys keep any kind of error log for forms or accounts

I can't seem to duplicate any issues either on embedded form. Were you able to ask them if there are any error on their screens or after hitting the Submit button?

Unfortunately we do not log errors on the forms. I assume that the issue is with their web browser, you can ask them if they can try using a different Web Browser.

Also what device they are using when they encounter the issue so we can trace it.

Thank you, let us know if there are any additional information.