Video stream keeps browser busy/stuck

I am currently building a media streaming web interface on Github. For the streaming part in PHP, I am using the following (slightly adapted) PHP class; VideoClass.PHP

Problem is, whenever I want to navigate away when it is streaming (either in videojs or directly), the browser will keep loading until a gateway timeout occurs. Currently the buffer is 100kb, so shouldn't be a problem.

Any ideas? I am using stream_get_contens() and checking connection_status().