Stop guessing and test Here is a link to a thread about testers

https://www.reddit.com/r/networking/s/6MFnkLAHLy

In my neighborhood if power goes so does Internet, but not Visa versa. This is because the equipment that my cable company uses needs power. In fact, on my property the power/telephone pole have a power meter on it that is for charging my local cable company. I know because I asked.

We use a TiVo DVR as well a local Plex server so when power or Internet goes out we have content.