These things are just little special purpose computers. Like their big brothers sometimes clearing things out by restarting them is all it needs.
Restart via Roku menu path Settings > System > System restart (Or for Roku TV: Settings > System > Power > System restart - just turning the tv off/on doesn't give a full restart)
If a restart doesn't do it, or if you don't have sufficient control with the remote to navigate the Roku menus, you can also restart by pulling the power plug to the device for a minute or so 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.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X