A number of TV manufacturers license Roku technology for inclusion in some set models and market them as "Roku TVs". Roku doesn't manufacture or sell "Roku TV" sets, it only supplies the Roku operating system.
This sounds to me like a hardware issue that needs to be referred to the manufacturer of the set.
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