OK, so I also got my automatons to function again. Granted I don't have as complicated as a setup like some of you, but I did follow some of your suggestions and was able to finally resolve my location-based automation issues (time-based and motion-sensor based automations were always working for me).
After completing all the previous steps (restarts of all devices, and only signing out of icloud on my Apple TV and back in again after a restart), my location-based automations still refused to function.
Following suggestions from many of you, I deleted my Home app, reinstalled it, and also deleted and recreated my automations. Now my automations work. When I left the apt, the "Leaving Home" automation turned off all my lights. When I returned home, my "Coming Home" automation engaged my lights scene successfully.
So in all, here's what I did that resolved this:
- Signed out of iCloud on my Apple TV
- Restarted Apple TV
- Removed my HomePod and HomePod minis from the Home app
- Fully deleted the Home app
- Reinstalled the Home app
- Signed back into iCloud on my Apple TV
- Re-enabled my Apple TV as a home hub
- Setup each of my HomePods once again
- Confirmed all HomePods appeared as home hubs in the Home app
- Deleted my automations
- Recreated each automation as they were before
I don't know if each of those steps is necessary, or maybe one set or two, but now everything is back to normal. To be clear, my Apple TV is my connected home hub once again, just as it was before the issue and during the issue. I suspect HomeKit data (possibly in both iCloud and in the home app and/or on the home hubs) was corrupted upon upgrading to iOS 16. Signing out of iCloud and then back in on my Apple TV, restoring the HomePods, deleting the app, reconnecting my Apple devices, and recreating the automations seems to have worked.
I've been submitting bugs and sending logs for a couple of weeks now, every time an automation failed to engage. Hopefully Apple is getting enough data to resolve this. I also sent them the above info in another followup so they are aware of what possibly resolved this for me.