This question has to be asked. Did you insert the batteries correctly? Some Roku remotes have the batteries inserted in the same direction, while others have one facing up and the other down. Look carefully in the battery compartment and see what the orientation should be.
Dan
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee, just another user.