I don't have the enhanced remote where there is sync button.
If there is no pairing button then this is a direct line-of-sight infrared (IR) remote.
Troubleshooting an infrared (IR) remote: • Of course, make sure you have good batteries installed. • Be sure the front face of your Roku is viewable and facing your viewing location. • Make sure there is nothing blocking the direct line between you and the Roku. • Check for interference with the IR signal -- some fluorescent lights may interfere, as can direct sunlight. • You can check if the IR signals are being sent in the first place by pointing your remote at a digital camera, even one build into a phone or tablet, and pressing some remote buttons. If the remote is sending signals you should see them flash on the camera view screen.
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.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X