I recently came across a Chrome issue which I think is worth sharing it with you.
I worked on a self written API using an HttpHandler which primary should return jso
In my case, the problem was cache-related and was happening when doing a CORS request.
Forcing the response header Cache-Control to no-cache resolved my issue:
Cache-Control
no-cache
[ using Symfony HttpFoundation component ]
headers->add(array( 'Cache-Control' => 'no-cache' ));