The arrival of iOS 16.2 represents a change in the Home application that was supposed to improve its operation, but the problems have ended up causing the withdrawal of Apple.
HomeKit has been the focus of many changes in recent months, with more to come. Compatibility with Matter and the new Thread connection protocol are some of them, but the Casa application was also going to be the protagonist with a new architecture that would substantially improve its performance, although the visual aspect of the app would remain unchanged. However, users do not stop complaining about bugs with the new update, until reaching a point where Apple has had no choice but to withdraw it and acknowledge the problems.
To update to the new House, the first thing you needed was the new version iOS 16.2 (and the corresponding ones on your iPad, Apple TV and HomePods). Once that is done, when you enter the Home app, a message appears informing you of the new update and asking if you want to apply it or not. However, from the moment you accept the change, the suspicion that things are not going to go well appears.. If Apple itself asks you several times if you are sure about the update and warns you that some users may lose access to Home... things are still a bit green.
Indeed it is so. Apple has acknowledged issues with guest users accessing your HomeKit network, even if they were already authorized. in my case for example all my guest users have disappeared, and when I send them the invitation again, nothing ever arrives. My location automations are also not working. I have no problems with accessories on my HomeKit network, in fact they work quite well and some even respond faster than before.
With all this, Apple has had no choice but to back down, and You can no longer update Home to the new architecture even if you are on iOS 16.2. Hopefully soon they will fix these issues and everything will be back to normal.