Hi Mikhayla,
I have observed that if the survey submissions were successful in past and only few individuals are encountering issues now, majority of it is to do with the submission contents/formats.
I would recommend to check following:
- Make sure the characters in text type questions are not exceeding character limits
- Attachments are named properly, i.e. No special characters and File extensions are properly specified (should not be FileName.pdf.pdf, FileName.jpg.pdf, etc)