Here is an article that will explain this issue.
I have a 6350TV, receiver, and DVD player. All connected via HDMI with ARC where appropriate. Netflix provides the Dolby Digital Plus 5.1 audio. When I use the Netflix app on the Smart Hub of my TV I get audio that has cut outs of less than 1 second duration as the video plays. These cutouts are not random. I can replay the video and the audio will cut out at exactly the same point in the stream. If I select the playback to be Stereo then these cut outs do not happen.
Now my DVD player also has an App for Netflix. When I use the Netflix app on the DVD player then the audio does not have cut outs.
When using the Netflix App on the TV my receiver reports the audio stream as Dolby Digital. When using the Netflix App on my DVD player the receiver reports (correctly) that the audio stream is Dolby Digital Plus 5.1.
Samsung was not help solving the problem with their Smart Hub App.
Does anyone know what is going on?