Hello,
once an URL starts with index.php/ you can be 100% it is not being generated by JoomSEF. make sure there is no other component / plugin active on your site, that might be interfereing with JoomSEF and modify the URLs.
JoomSEF generated URL will never include "index.php". Either you will see just SEF URL, alternativelly with a few variable appended behind "?" questionmark (such as some-sef-url?limitstart=10) or you should see original Joomla non-sef URL in case it is not being processes by SEF engine by some reason.
If you see URL as you have sent, it might be some code interfering (as I mentioned above) or the source component self is generation or modyfing it from some reason.
You can make sure that it is not JoomSEF URL by looking in the JoomSEF URL Manager records.I am sure you will not find it there.