Login vs Download (mass edit?)

I have a very large document library on a client site, and we’ve noticed that some files say “Download” and others say “Login.” I’m not sure why there’s a discrepancy since I used the same method/settings to upload all files. It seems that I can change them through the Batch Edit feature, but I still have to manually find all the files without a checkmark in the “NM = Downloadable by Non Members” column and then manually add the checkmark. Am I going about this the wrong way? Is there a way to ensure that all files can be downloaded without people having to log in?