Yamaha RX-A730 issue with some 6.1 audio track movies

[PUsokrJosh305]

Hey Everyone! My family owns the Yamaha RX-A730 receiver and uses it as the home theater receiver. Over the years, we have played many movies and tv shows through it. What has always puzzled me though is that some movies with 6.1 surround sound audio tracks will be outputted as 5.1 rather than 6.1, yet the receiver detects it as 6.1. I notice this more with the first two Harry Potter Ultimate Editions that have a DTS-HDMA 6.1 audio track on them. What's really bizarre is that our oldest Yamaha non-HDMI receiver outputs it at 6.1 and our other Yamaha receiver, the RX-V565, also outputs the movies in 6.1. But for some reason the A730 does not. Did Yamaha change the way their receivers interpret how to output movies in 6.1 with their Adventage line? I have the extended surround sound option off, which allows the receiver to playback the original audio track of the film but for some reason, it plays some 6.1 tracks in 5.1. Any information would be helpful, thanks!