Why am I seeing H28 warnings?
I'm seeing intermittent H28 warnings in my router logs and on the dashboard.
The best place to describe what is happening here can be found here. Your app was probably waiting for the full request to be sent to your app before processing it. However, this never happened because the Content-Length was larger than the amount of data sent. After waiting 55 seconds for the additional data to be sent the connection was terminated.