I have uploaded a xlsform 2 weeks ago and yesterday after i downloaded the csv results and sterted working on it i noticed something strange which has never happend to me before and i can't explain it. In this form I had more than 30 select_one questions, 4 select_multiple questions and 30 text field. Out of all this questions I had missing data on this 4 select_multiple questions from only a specific interviewer.
all the questions were required. I have tested it and you can't submit the survey if you haven't checked all the questions. Also I contacted with the interviewer and he told me that he has filled the questions.
I can't explain why this happend, because the same interviewer is working on another xlsform and the data are coming correctly from this other form. But at the one that I am talking about the data is missing at select_multiple questions.
Thanx in Advance.
Missing data from multiple choice questions in a specific xlsform from a specific surveyor(username)
A reason could be that your form changes touched these 4 questions (e.g. choice labels, type, name). For example the user may have used the older form version.
You may have a look, please, at the version (metadata) and other columns in an Excel export downloaded with all versions options.