Why aren't some of the flagged positions showing up on an imported excel spreadsheet that was created in getprospects?

I've uploaded numerous spreadsheets with records of professionals and business people that marks/identifies their position. 

I've also created a custom flag 'position' and matched it with the job title when I finish importing the file itself. 
However there's a raft of entries where the position is blank when I look through contacts. 

Why could this be?  

Thanks in advance.