I could reproduce the issue with this sample code in both of the environments below. Xcode 16.0 (16A242d), iOS 18.0 simulator Xcode 16.1 beta (16B5001e), iOS 18.1 simulator

Same here. Any solutions?

Edited: I found that just rebooting macOS solves this issue. Setting host application was not needed. In my case setting Host Application in the test target settings > General > Testing from "None" to the main app solved this issue.