Download these four files into one directory, then run npm install and npm run dev with Node 22.12+ or a compatible newer release. Open the displayed local URL and click Reproduce.
With Ionic Vue 9.0.6, the result is TypeError: Cannot read properties of undefined (reading 'ionPageElement'). On Safari the wording is undefined is not an object.
This is a deterministic callback-level reproduction: it uses the real Ionic router and outlet, pushes a second page, verifies that a back destination exists, returns to the root, then delivers swipeHandler.onEnd(false) as a late cancellation callback. It deliberately models the event ordering rather than attempting to reproduce the physical gesture/animation race. No view-stack or router mocks are used.
After guarding the missing view/page in Ionic Vue's IonRouterOutlet cancellation branch, the result is PASS. Normal swipe cancellation must still hide the entering page when it exists.