Leave without saving warning missing when using browser navigation

Describe the Bug

When creating a new collection item and using the browser's Back button, the warning about unsaved changes does not appear. However, this warning is displayed when navigating using a UI link (e.g., another collection or a breadcrumb link).

Not sure why previous issue was closed as duplicate (didn't find any issue like this) - https://github.com/payloadcms/payload/issues/14854

Link to the code that reproduces this issue

https://github.com/payloadcms/payload/tree/main/templates/website

Reproduction Steps

Go to a collection with autosave disabled (ex. users)
Create new item
Type at least one character in input field
Hit back button
Browser navigates back
Expected behavior: "Leave without saving" warning should be displayed

Which area(s) are affected?

area: ui, area: core

Environment Info

Binaries:
  Node: 20.19.0
  npm: 10.8.2
  Yarn: N/A
  pnpm: 10.3.0
Relevant Packages:
  payload: 3.67.0
  next: 15.4.4
  @payloadcms/db-sqlite: 3.67.0
  @payloadcms/drizzle: 3.67.0
  @payloadcms/email-nodemailer: 3.67.0
  @payloadcms/graphql: 3.67.0
  @payloadcms/live-preview: 3.67.0
  @payloadcms/live-preview-react: 3.67.0
  @payloadcms/next/utilities: 3.67.0
  @payloadcms/payload-cloud: 3.67.0
  @payloadcms/plugin-seo: 3.67.0
  @payloadcms/richtext-lexical: 3.67.0
  @payloadcms/translations: 3.67.0
  @payloadcms/ui/shared: 3.67.0
  react: 19.1.0
  react-dom: 19.1.0
Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.5.0: Tue Apr 22 19:54:25 PDT 2025; root:xnu-11417.121.6~2/RELEASE_ARM64_T6020
  Available memory (MB): 16384
  Available CPU cores: 10

Start with the templates/website reproduction and verify the behavior on a collection with autosave disabled: create an item, edit a field, and use the browser Back button. Compare this with navigation through a collection or breadcrumb link; the work is done when both navigation paths show the “Leave without saving” warning for unsaved changes.