Why does my outdoor Nest cam advertise when it’s not operating?

I’ve had an outdoor Google Nest cam in front of my house for at least 7 years. The cam itself is amazing. We’ve literally had nor’easters and countless other severe storms come through, and it hasn’t moved. The range I set years ago is still the view I still get. And it’s not covered or protected in any way. But I could still move it with my hand if I wanted to. It’s never been cleaned, but still gives me a perfect clear view all the time.

it also has a solid red light on most of the time. I assume this is to alert people that they’re being recorded. Totally fair. However, I recently got a new router and neglected to connect it to the cam for a few weeks. During this period, the solid red light switched to solid blue. Why? Fortunately there is almost no crime in my neighborhood, but why would the cam let the outside world know that it’s not operating? There’s the app, an email, a text, etc. that could alert me. But the blue light is pretty much a message to wannabe intruders to “come on in”.

Google Nest says that sometimes it shines blue when the router is too fast at 5G. I don’t have a Nest but I read it’s not compatible with a router above 3G. That’s kind of a bummer.