Hey @mx_ryabov ,
It appears you may not be using the canvas elements correctly, and it may be causing the issues with garbage collection. I see you are calling stopRender on the old canvas and startRender on the new one, but typically, you should be called on the exact same canvas.
In addition, our API allows users to draw multiple streams on a single canvas, so I would encourage you to take a closer look at our demo app. 
If you are able to reproduce the issue on our sample app, and provide steps to reproduce with screenshots of the problem, then that’d be a helpful for us to investigate further.
Thanks,
Tommy