Yamaha HTR 5740 no surround sound with DVD

Question

My receiver will not play surround sound on the DVD. I ran a test and all of the speakers are functioning. Went through the manual again and again. I get sound from all of the speaker but can not get the surround to work. It is as if the signal coming from the DVD player is stereo only but they are surround cabable DVDs that I am playing.It did work fine but I just recently set it up in my new home and the surround function went away somehow.Any ideas.