when redirecting, a 0kb file is downloaded

This is the weirdest thing could ever happen. I ran a php script of redirecting about 200 urls with a particular category to be sent to product detail pages and they worked fine on my local machine which is windows. our staging server is nginx, so I think it should be from some configurations but I cannot figure this out. Could you please let me know what you think about this? it will redirect to right page but does not reload the page and then download a file with the name of url and the file is 0kb. it seems that I have the same .htaccess file, but server configurations are definitely different. ​Thanks, Negin