I'm in the same boat, no relief is had by wrapping the column in a ZStack. iPhone build works as expected, iPad only updates the detail view once, then no more. Detail view .onAppear is not accessed after the first update. Using release version of Xcode 14.2.

Same issue occurring with iOS 15.3. Broke my app with no official work-around available. Glad I'm not trying to make money with this.