I am having the same problem. My new voice remote did work and change channels on my wowway cable listing. I have a Sharp Roku TV, then after about 4 months it just stopped changing the channel. It would go to do a search with the channel number on channels in Tubi Hulu Roku etc or titles with that number in it. I don't know why it quit working I have made sure my software is up to date. My wow cable has about 208 channels and it is very frustrating to have to scroll up and down to get to a particular channel. I have checked out all topics on Roku and help sites.
So what is the answer
A Roku voice remote does commands such as "launch Disney" or find "The Fast and the Furious". A Roku voice remote does not have the ability to take commands once you are within a channel such as watch DirecTV Stream and saying "Go to HGTV". That is not how it works.
https://support.roku.com/article/360009552694
"Note: Not all channels support all commands. We continue to evolve and expand Roku Voice, with a focus on helping you get to your favorite content quickly. We are continually working internally and alongside channel partners to expand functionality and expect it to improve over time."
