I have owned a Roku 4K and I recently bought 3 more Roku 4K+ units. All 3 remotes turn on/off and volume. One remote does not "Hear" voice commands. I bought all 3 directly from roku.com through email offers they sent me. Can I return the remote and get another? Thanks, David Moore
Roku warranty claim instructions: https://support.roku.com/article/208757058
Note that remotes do not have serial numbers. When serial number is requested, Roku suggests you enter the serial number for the Roku unit you are using the remote with.