Can't see files on my Mac, I do see them on web..

The collaborating folders I got an invite to are empty, I can't see the content but when I view on web I can see what's inside the folders.

If I copy a file into the folder it disappears after a few seconds but my co-workers can see the file I put on there, and I'm not able to.

Anyone got a suggestion for this issue??

Thanks,

Mike