After several days of playing around with this issue, I noticed that the Organizer window had two entries for my App: one was "com.myname.appname" and the other was "com.myname.appname-SAMPLE-CODE-DISAMBIGUATOR-". For whatever reason, my new builds were being placed under the former. When I changed the name of my Bundle Identifier, in Xcode, to the later the new build was now under the later and everything worked as expected. I was able to Validate and submit to Apple for review. Not sure why this worked but will certainly remember the experience.

Thank you for the link regarding NavigationSplitViewColumn. Unfortunately, this function is in beta and not available until the release of iOS 17. I may release the App for iPad(iOS) and macOS and re-release for iPhone(iOS) when iOS 17 becomes real.

Please see trivial example of above issue with NavigationSplitView not working on smaller iPhones. Works as expected on iPads and iPhone Pro max, but the detail view does not appear on SE, Xr... and smaller iPhones. Should see a simple parabola on the detail view and the text "This is the sidebar view" in the sidebar. When you run the code, the detail view will appear first on the large iPhones. When you run the code on smaller iPhones, only the sidebar will appear. Thank for taking a look. // // ContentView.swift // Trivial plot // // Created on 8/09/23. // import SwiftUI import Charts let xData = [-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10] let yData = [100,81,64,49,36,25,16,9,4,1,0,1,4,9,16,25,36,49,64,81,100] struct ContentView: View { var body: some View { NavigationSplitView { ScrollView { Text("This is the sidebar view.") } /* End ScrollView */ } /* End NavigationSplitView */ //************************** Detail view here ********************************************* detail: { Chart(0..<xData.count, id: \.self) { index in LineMark( x: .value("", xData[index]), y: .value("", yData[index]) ) } .foregroundStyle(Color(.sRGB, red: 0.999424, green: 0.985554, blue: 0)) .chartYScale( domain: .automatic(includesZero: false, reversed: false), type: .linear ) .chartXScale( domain: .automatic(includesZero: false, reversed: false) ) .chartXAxis { AxisMarks(values: .automatic(desiredCount: 10)) } } /* End detail: */ } /* End of Body: Some View */ } /* End of Struct ContentView */

Never mind... I figured it out by trial and error. Thanks for looking.

Thank you Dirk-FU. In retrospect, your explanation makes sense and I am beginning to wrap my head around declarative vs. imperative programming.