Perhaps the problem is not with the remote but with the Roku's response to the remote.
Have you tried pulling the Roku's power plug for a minute or two then plugging it back in?
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X