Just because one source worked fine with your receiver doesn't mean a different source will, especially if they were plugged into two completely different and settings-independent ports..
When you're watching Hulu Live in your Roku, what is displayed on the screen on your receiver? This will tell us if you're in a surround mode that's causing audio to play out of incorrect speakers. Hulu Live and Hulu Plus only play in stereo, so if you've got your receiver set to some kind of "simulated surround" mode, you may to just set it to auto or just stereo.
What is the model of the receiver, by the way?
Yeah, I got some Rokus.
https://youtu.be/d1CSEeqWl10