How are you powering it? If you're using the TV's USB port, try using a USB power adapter plugged into the wall that can supply at least 1 Amp. If you're already doing that, try a different one as well as a different USB cable.
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.