Apple TV stopped connecting after a power outage

an electricity spike could've torched it,

if it was me then I would bring it to to a friend / relatives house and see if it works on their network

if the same thing happens then I would say hardware defect

WiFi or ethernet cable? What do you see on the Settings > Network screen (it usually shows network config details)? Assuming you see an IP address, subnet mask, router, etc. what happens if you try Settings > System > Software Updates > Update Software (this'll cause the OS to check for available updates)?

I had this same issue after installing a smart plug to turn it off every night. I found it’s a simple answer albeit inconvenient. Everytime I start it up the next day it says no internet connection. Go to setting and Down. to system, hit restart. It works everytime for me. Inconvenient sure.

Looks like a message from a tvOS App. Which one? Where are you located?

Where are you located? This has nothing to do with power.

Try deleting the apps and re-installing.