Yes, I am also seeing this. More specifically: for me the perform() is called as long as my app is open when I change the Focus mode. But, if my app is in the background, perform doesn't get called.

I have ran into the exact same issue. I also created a new model before I added the fetch indexes in the model editor. In my testing the migration was working correctly, but in production I am seeing quite a lot of crashes. I suspect there is something wrong with the lightweight migration when the fetch indexes are involved. Probably it's not a very widely used feature, that's why it's not getting more love from Apple. From what I've been able to tell in my crash reporting tool, it only crashes once per user. So hopefully on the second run it works for them, but I don't know that for certain and that worries me.

I am experiencing the same issue. I have looked through the Console logs and seeing pretty much the same thing as @JagCesar2 . It would be great if this could be fixed soon, because I'd love to test the logic of performing sync with my server after the app is opened by tapping on the live activity, and then displaying the relevant screen. I have submitted a Feedback for this: FB14754576

I'm also experiencing the same issue! Probably something wrong on Apple's backend. Hopefully they will fix it soon.

I'd love to hear an answer about this as well.