Remember that these new sticks replace the old Roku Express and Roku Express 4K, but they’ll be sold alongside the existing Roku Streaming Stick 4K from 2021. So in the UK, we now have: ...

There might also be a physical reset button on your Roku TV (often a small recessed button you need a paperclip to press) that you can hold in for about 10-30 seconds while the TV is powered on.