Missing​‍​‌‍​‍‌​‍​‌‍​‍‌ fields most of the time occur due to the vCard format that requires standard field names while the Excel sheets usually have custom headings. When people try to use a simple Excel to VCF converter, the tool is not able to find the unique columns, thus the information like company names or addresses becomes disappear. It is a good method to rename the columns to standard titles and remove the characters that can interrupt the mapping process. Before they Convert Excel to vCard, many users take this step. Also, tool with organized mapping can facilitate this problem being dismissed. The OSTtoPST App Excel to vCard Converter is a perfect example of a tool that can do this because it is able to keep every field when converting from Excel to vCard, thus it is very little data that gets ​‍​‌‍​‍‌​‍​‌‍​‍‌lost.
more info: https://www.osttopstapp.com/xlstovcf.html