Prompt breaks back button in iOS Safari

[Trying2KnowMyself]

1. Add a <Prompt message="something" when={true} /> to a page in inferno-router-demo and run it
2. Access the demo using Safari from a device running iOS (tested with several versions, including 26.5)
3. Navigate to the appropriate page using the links
4. Navigate from the appropriate page using the links
5. Observe the prompt, accept it
6. Navigate to the page again
7. Attempt to navigate away from the page using the back button in the browser

Expected:

Prompt

If no prompt, navigation is not blocked

Actual:

No prompt, navigation is blocked

[Trying2KnowMyself]

To clarify slightly: the back button is always broken in my experience, steps 4&5 just demonstrate that it’s working in some scenarios and aren’t truly necessary for reproduction so long as there’s history you should be able to navigate back to.

I initially suspected this was related to beforeunload not being properly supported on iOS:

https://bugs.webkit.org/show_bug.cgi?id=219102
https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event

And I haven’t dug in deeply enough to understand how router.history works, but I don’t actually see that event used in this repo.