"like it should" means?
If i doesn't sound correct when you play a disc then the problem is inside the HTS. If it sound fine with the disc then what is the problem with the TV?
No sound?
Bad sound?
No surround sound?
Check the audio settings on the TV. Change the surround mode on the HTS. Each Roku channel may put out different audio so may need a different setting,
Is the HTS connected so it gets digital audio from the TV?