What causes sync'd excel to miss Forms responses?

DingkunXie Thanks for replying! Right, I can see responses in the Forms Responses view that are not in the Excel. The count in the workbook effectively goes 1, 2, 3, 6, 7. If I were to sync all responses to a new notebook, (which I did regularly during the testing phase of this form,) we would lose all the formatting and comments that make this excel legible to the people who need to view it. The people using the form are very invested in making sure it continues to work as expected, so if I can figure out what action made it temporarily skip synching, then I can tell them not to do that action and trust that they will follow instructions.

If I can't figure out what action caused the skip, my next best option is to create a second excel full of formulas to pull all the data out of the first excel, and format the second excel in a legible way. That way, if we need to resync the first notebook, the formatting doesn't need to be re-done. But obviously this option is a lot of extra work - it would be better if I could just tell them "don't do [thing]".