No rear or sub noise

Maxnifi MaxSR on firmware 103 no sound from rear speakers. This is the 2nd Soundbar I received. Same issue, once we set it up with google home. Now we get rear and sub sound if watching Amazon or internet apps but not from cable. It has to be how the cable is hooked into the tv. I spent $500 to have surround sound on all tv shows. Who can help? I have called and was supposed to receive a call from level two support but never received any other communication from Polk support.