Can't get surround sound from Roku 3

[laurav66]

I have a Roku 3 device and a Blu Ray player connected to a Sony STR-DG1000 A/V receiver via the same HDMI switcher. The Sony receiver settings are configured to automatically select whether to use surround sound based on the audio signal being sent. I get surround sound when using the Blu Ray player, but not on any channels on the Roku. The Roku audio settings are also set to "auto," and in the bottom right corner of that screen it says it detects a couple of surround-sound signals. But the only sound that comes out is stereo. Any suggestions for further troubleshooting? Thanks.

 

[laurav66]

I should add that I tried bypassing the HDMI switcher and that did not solve the problem, so I can only assume it's related to the Roku or the Sony receiver.