File upload: why is my Excel spreadsheet locked when I uploaded it to SharePoint?

I blocked certain columns in my Excel spreadsheet so that nobody inadvertently put data in those columns. But I also made sure that the specific columns of the spreadsheet were editable so that people who need to update their data can do so. When I uploaded it to SharePoint, I noticed that the entire spreadsheet is now locked. Areas that were previously editable, before loading, are now locked. How can i solve this?