Form entry did not populate sheet


I have a form that I have been using with my team for over a year now successfully and today a user submitted an entry using the form, however when reviewing the sheet, the information feeds to no line-item entry was there. The user did get an email notification with their submission confirming that the entry was successfully received. I have also reviewed the sheet history and do not see anywhere where this form was received by the sheet. Has anyone ever had this happen before?