Black rear camera when accessing web application from Android Phone/Tablet

I am making a web application in Ember.js I want to access one of the pages from a mobile device such as phone or tablet. To access the cameras I am using HTML5, Javascript and MediaDevice interface. Everything works as expected when I access the web application from my laptop. The web application can recognize and successfully load both cameras. (one at the time).

The problem starts when I want to access the same web page from the android phone/tablet. I am able to toggle between two cameras (front and rear) but the back camera is black (seems like switched off). If I start the camera separately (with native camera application) and then access the web page I am able to see the view from the rear camera. Strange thing is that the front camera works all the time no matter what. I assume there must be something wrong with the permissions that grant access to the back camera's feed.

Did anyone else had that problem before?