I have several Roku cameras, and I did have one of the simple indoor cameras simply fail. Nothing I could do could make it work again, and Roku replaced it under warranty. It was the camera itself that failed, as it would not detect the QR code to set up the connection.
Dan
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, just another user.