CSV format issue: wrong decimal separator or CSV delimiter

First, select the right CSV delimiter in Rock Mapper under Settings > General. 

Second, go the iOS Settings General > Language and Region > Number Format and choose the format that you’d like to use. The Thousand Separator is only used internally in the app, but the decimal separator will be used for numbers in the exported CSV files. In other words, Rock Mapper will inherit the Number Format that you’ve picked in the iOS settings. 

Last but not least, please check what you’ve set as decimal separator and thousand separator in the programme that you are using to open the CSV file (e.g., Excel).