Except, it turns out, someone in my household did. It's just not sold as a Xiaomi device. It's a vacuum, specifically a Roborock S4. That robot sits idle for 2-3 days, does 45 minutes of work, then goes idle again. And when it's idle, tucked away under a bench, charging it's little battery and complaining on the app about dirty filters, it's pinging those two addresses 119,000 times a day.
|I mean come ON|
So, if you're seeing crazy traffic on your network and need a place to start, look for down-market IoT devices that may have borrowed tech from Xiaomi.
If you have AdGuard, the custom filtering rules you want are:
If you're there adding those, toss in this one for your noisy Rokus as well.