HomeKit Connection Issues
Symptoms:
Sometimes my MacBook Pro, iPad Pro, or iPad mini connect to WiFi at home but can't get internet access. I have to reboot my TP-Link Deco mesh network to get them to connect. Also, my Logitech Circle View Doorbell randomly reports being offline and online.
Short Answer:
It appears that one of my HomePod minis is the hub for HomeKit and it is causing these problems. I haven't diagnosed the issue with the doorbell beyond unplugging my HomePod minis and having it stay online. I was able to trace the other problems to the HomePod minis though.
Technical Answer:
I called tech support at TPLink and they were great. Really helped me dig in. We ran a WireShark trace on the network and found the problem. It appears that the HomeKit hub is assigning an IPv6 address that starts with "fbdc" which restricts internet access. HomeKit uses IPv6 address for its internal HomeKit networking. For some reason when one of my devices has been away from the house for a while then connects to WiFi, it gets the IPv6 address but no IPv4. The HomePod mini assigns it rather than my WiFi router. I don't understand how or why.
I'm not sure what is going on with the doorbell. One of my mesh remotes is close enough to it to give it a good signal. As I said, if I unplug both HomePod minis, the doorbell remains online. I had them unplugged for a few days to verify. I think the latest update, 16.4.1, made it better but didn't completely cure it.
If anyone has anything to add to this, I'm interested.