Did you recently receive an update to Roku firmware version 9.3? (Check via Settings > System > About).
Several people with problems after receiving the 9.3.0 update have reported success via the suggestions in this post:
https://community.roku.com/t5/Remotes-Accessories/Roku-Streaming-Stick-remote-fails-after-new-system...
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Do not ask me 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.". Please only do this if it ACTUALLY solves your problem.
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X | Streaming Stick 3600