I am experiencing the same problem. The way to reproduce it is simple, just create a simple Model in SwiftData, query it in View and display it in Swift Charts. When I start the app, the display is instantaneous, but then the CPU shows 100% for a few seconds. Xcode Version 15.3 (15E204a)

I have same issue. Using utf16.count did not cause a hang. The problem did not occur when the emoji was not at the end. ex) let message = "Hello 😂 A"; I believe the difference between message.count and message.utf16.count has something to do with the hang of the symbol with the emoji data split at the end of the string. However, I don't know why this problem occurs.