Google Sheets Integration Keeps Breaking

For all three of my active forms, I have had to remove and recreate the integration with Google Sheets repeatedly over the past month or two as it keeps breaking (i.e., new submissions suddenly stop transferring). This doesn't affect the integration with Google Drive. For now, no additional submissions are required, but this will change again in a week or two. Any leads on why this might be caused? I asked the other users who are reporting they aren't modifying the sheets.

We do not recommend to modify integrated spreadsheet or change it's settings as this can cause the integration to fail. Also, moving submissions or deleting them can also affect the integration. 

In rare cases new submissions can be not forwarded to the sheet if our system receives errors from google. For this case, we have an internal script, which allows to push missing submissions to user's sheet, you may contact us on this matter if needed.

If you need not only to review submissions, but to also manage them within a sheet, I can suggest to use IMPORTRANGE function to copy the data to different sheet and apply changes to that sheet.