In fact, always. Try another model or find where to change TV and the Netflix app to PCM or stereo.
As to your last question, it's a common complaint on the web about these convertors.
I have a new Samsung UN50NU7100FXZC tv with Optical out audio going through a converter to analog audio connected to an older Koss KS2100 Home Theater system. All works fine when watching tv, however when I start the Netflix app the picture is fine but audio is just a lot of electronic noise. Other Apps ( You Tube etc. ) work fine with the sound coming through the theater system. If I switch the audio output to the TV speakers the Netflix sound works, but I'd like the sound through the theater system. Has anyone else experienced this? Any suggestions would be greatly appreciated.