Download masking - done and undone, 404 error

I am making an online course and inserted some links to downloadable pdfs.

They were protected to start out, but then I ran into an issue where the pagination buttons that have links built were being masked and not working. So I turned deleted all the protected groups in Options>Media to test if the pagination links would work. I got those to work, but as soon as I added in a Protected Group, it masked those and broke 'em again. I don't really care too much about that....

What I need help with is the download links. They are masking...that's great, but when i click the links it gives me a 404 error.

I tried changing the masking type, the masking fake path name and activating and deactivating the plugin.

Is there some type of reset I need to do?