Here’s my problem; I have a Vizio E-50 C1 TV connected to Spectrum cable with a DVR and an old Denon AVR-3803 surround receiver and speaker system. Up until recently I was able to smoothly shift from surround sound cable broadcasts or DVR playback to Netflix or Amazon TV streaming, and the system would adjust itself automatically to the surround sound system when I made the switch from cable to streaming. Now, however, the surround sound stays only on the cable audio and the only sound available on any streaming service is through the tinny speaker of the Vizio TV itself. To check it I tried a Roku device, same result. Any suggestions?