Apple home shows incorrect accessory status in both iOS and MacOS

I shall try that in due course, but there are good reasons not to be an early adopter of any Apple major software release. First let the other people find the bugs, because there will undoubtedly be more of them than just the one you want to fix. Always wait until X.0.1 at least before you dive into the unknown.

And the answer, "install the next level," is the most frequently touted and least successful of options. There's nothing here:

macOS Sequoia 15 Release Notes | Apple Developer Documentation

or here:

What's new in the updates for macOS Sequoia - Apple Support

to indicate that the problem is fixed by this release. That it has persisted as a bug for more than three years suggests that it's below the horizon and that Apple doesn't really care that much about it. Having spoken to Executive Relations recently about a different problem, I know that their effort is concentrated on Apple Vision, not the little systems or products.

I decided to take the bull by the horns and upgrade simultaneously to Sequoia, iOS 18.0.0, and tvOS 18.0.0

That was a disastrous decision.

The status shown on the iPhone and Mac apps is still in error, except that, instead of the same lamps showing false positives when the last person leaves home, then turning on when they’re switched off in the apps, any light can indicate a false positive. Sometimes only one. Sometimes half a dozen. When any of them is turned off in the app, the real bulb turns on.

In addition, 3 out of 4 groups of lights no longer respond as groups.

I had these set up on shortcuts which run when no activity is detected in the room. The shortcuts ran flawlessly until the upgrade. Now those light groups don’t respond to the shortcut command “Set <accessory>” correctly. 

Either nothing happens, or they go off when they’re supposed to dim, or they fail to change hue. Or one member of the group - usually the one previously identified in the “Get <accessory>” obeys the command, and the others fail to.

Meanwhile in the IKEA app, and with the IKEA remote controls, everything continues to work exactly as it should.

The problem is clearly in the Apple interface.

I removed one group of lights completely from the IKEA hub, then reintroduced them with different names, and put them back into the correct place in Apple Home.

However, several of my scripting commands then failed to work in the iOS Home app. Not because the light names had changed, but because the old statements that referred to them could not be updated either to the new names or in some cases to the correct attribute.  For example, an old statement “Get Window-light power state” would take the new name, but would then only allow Hue as a variable. The following “If” group would also only recognise Hue.  By deleting the “Get” statement and inserting a new one, it is possible to get the correct attribute from the correct bulb, and only then does the corresponding If group work correctly.

Even so, this is better than the Mac interface, where inserting a new “Get” or “Set” statement does not necessarily guarantee that it can be populated.

My next step will be to write an automation triggered by a dummy switch when the last person goes away. This will test each accessory in turn and switch it off only if it is on. I hope that will fix the problems caused by using a scene directly triggered by the last person going away.

I shall persist until I have rectified all the problems previously mentioned, and fixed those caused by upgrading the various software levels.