I am unable to comment due to the lack of reputation points, but I tested this on iOS 16.7.10 (iPhone X) and I cannot reproduce your issue. Could you update your post with more information, such as where it was produced (debug or release), the phone and iOS version you used?

I'll edit this answer with a solution after you provide us with more info. In the meantime, I can only give you a potential answer to this:

VStack {
  Button("Test SWIFTUI") {
    sShowing = true
  }
}
.fileImporter(isPresented: $sShowing, allowedContentTypes: [.item]) {result in
  alertText = String(describing: result)
  showAlert = true
  sShowing = false // Maybe this is what you need? Setting it back to false might address your problem
}