Home button no longer swaps to source for Roku

As makaiguy mentions, this is a function of CEC, an HDMI control standard. It requires both the Roku and your connected device (TV or AVR) to also have CEC enabled. Sometimes the problem is figuring out what the manufacturer actually calls the setting. Roku labels theirs One Touch Play, although some devices also have CEC mentioned in the menu. Samsung calls theirs AnyNet+, and so on. You need to ensure CEC is enabled in all connected devices. I can say it works just fine with my Ultra. I hit the Home button, the TV and AVR power up and change to the correct input on both devices. Never had any issue with it. 

Always a small chance the HDMI cable has suffered a failure, allowing the video to pass but the CEC commands aren't making it across.