HomeKit issues linger under iOS 12
HomeKit has suffered from persistent connectivity issues in the past, notably with iOS 10, but these were largely fixed with the release of iOS 11. Assuming you have adequate WiFi and Bluetooth coverage for your devices, HomeKit users have had smooth sailing for a year. However, with the release of iOS 12, multiple users have reported a plethora of issues, most notably with Bluetooth devices. These issues have been confirmed via a few device makers, and while we’ve seen several bugfix releases for iOS 12 to date, some of these issues appear to be lingering still.
Initial reports started to emerge fairly early, with Schlage Sense and August smartlocks encountering response issues. User questions began to appear around the same time, with issues ranging from No Response on certain devices, to issues with automations not working, or notifications based on presence firing at the wrong time.
Elgato, maker of Eve bluetooth devices exlusively for HomeKit, confirmed that they have identified numerous issues and raised them with Apple.
Connection issues to all bluetooth devices
Shortened bluetooth range (Nearly halved)
Home-hubs (Apple-TV, iPad, HomePod) goes into 'sleep mode', and won't trigger communication for rules, scenes and timers
Historical data will stop working after 10% (I suspect they refer to the historical data on their own temperature sensors)
Users with more than one home-hub will experience issues
"Admin failure"
This list appears to be mostly complete and concise, with the addition of geolocation based notifications firing incorrectly on occasion, such as sending alerts for events all the time when they should only occur when nobody is home. Since the release of iOS 12.1 things have improved somewhat based on anecdotal reports, but users are still getting varying results.
So what can you do if you are encountering odd behavior? The best advice is to restart your home hub. This will restore functionality for a time, but it appears to be temporary. You may find things getting flaky again within a few days. If you have more than one home hub, you’ll need to restart them all, or disable the extra ones (standby status in the Home app). In some cases this isn’t practical if you need them to provide adequate Bluetooth coverage.
If you’re using an Apple TV as a home hub, or using one to extend range to some remote Bluetooth devices that are specifically exhibiting issues, you may find waking it up will be enough. If so, it may be prudent to go into the Apple TV General settings and disable sleep mode for the time being. Of course, if you’re using HDMI-CEC to turn the TV on and off you’ll need to revert to using two remotes for now (the horror).
It may also help to ensure that the iPhone and iPads associated with the ‘owner’ of the home are hard reset. It’s always a good idea to do this after every update installation anyway as it tends to resolve battery drain issues that typically occur.
Beyond ‘turning it off and on again’, there isn’t much we can do as end users. Hopefully iOS 12.2 will bring some good news regarding these issues.