While working on the iPad UI variant for our iPhone video subtitles app Captionista, I noticed that when swiping to dismiss in compact horizontal size class or on iPhone, the popover transition freaks out — as recently as iOS 14.1 and SwiftUI 2.

Workaround: Do the “adaptive” part of popover presentation on compact size classes yourself – if the horizontal size class is currently compact use sheet instead of popover. You could probably roll your own View modifier to achieve this more graciously, but here’s the low-tech solution to keep the example simple:

struct YourView: View {
@Environment(\.horizontalSizeClass) var sizeClass

var body: some View {
    VStack {
      if sizeClass == .compact {
          Button(action: { showSheet.toggle() }) {
             Text("Settings")
          }
          .sheet(isPresented: $showSheet) { 
              YourView()
        }
      } else {
          Button(action: { showPopover.toggle() }) {
             Text("Settings")
          }
          .popover(isPresented: $showPopover) { 
              YourView()
              .frame(width: 300, height: 500) // Set a size for Popovers
        }
      }
    }
  }
}

This one has a Feedback: FB8889254 “SwiftUI popovers do not transition correctly when swiping to dismiss on iPad or iPad (h-compact split view)”