I suspect your power outage was “messy” and jumbled some info in the Roku.
I think I would try a factory reset: (About half way down this page. You’ll probably need to use the physical button method)
https://support.roku.com/article/208757008
Make sure to hold the button for long enough to not just do a simple restart.
You will need to re-enter your Wi-Fi info and re-link it to your Roku account so you might want to collect that info before you start.
Banned but back. Because why not?