I once had this problem. In my case I found that it was caused by my multi-lingual setting which redirects accesses to index.php to /en/. Then I needed to add "/en" in the middle of the URL. Don't know if it is your case, but worth seeing. Check your apache access log and see any 301 return codes. Please check also, by verbose curl output to see any terms about redirect.
The command you are already using doesn't work if the URL has variables appended to it. That's why I asked you to contact your server support team to get the command for this kind of URLs.
