In my case, my project is a Unity project so I am setting(or changing) my icon on the Unity project and there was no change. What I have done to change; Found the AppIcon.appiconset folder in Xcode Project folder and deleted(Finder on MacOs). 2)Find my AppIcon in Unity-iPhone->Data->Images (Project Navigator in Xcode) 3)Drag and drop Images to some where in the main project folder (Project Navigator in Xcode) And that fixed my nightmare. Hope helps someone.

Updated Monterey 12.0.1 & Xcode 13.0 and still gettin "Cannot find type 'PhotogrammetrySession' in scope" error.