Are you using ODK Central?
Reading through some other threads:
- Another possibility is that your hosting service is behind a proxy (e.g., Apache HTTPD) and that proxy is adding or stripping headers from the requests. One of these headers specifies the incoming character set, and if absent, will cause this issue. (from ODK in different languages - #17 by Mitch_S)
- This could be an encoding problem on the spreadsheet tool side. You should try to force the encoding while opening the csv to UTF8. Are you using Microsoft Office? It can be troublesome when dealing with CSV files. I've heard that LibreOffice tends to have fewer issues.You might also try searching the internet for general guidance on opening CSV text files in Excel, for example: https://stackoverflow.com/questions/43307776/how-to-open-a-text-file-with-excel-in-utf-8-encoding