On-demand revalidation inconsistent on App router vs. Pages when deploying to Vercel

[Windsorborn]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: darwin
      Arch: x64
      Version: Darwin Kernel Version 22.5.0: Thu Jun  8 22:22:22 PDT 2023; root:xnu-8796.121.3~7/RELEASE_X86_64

Binaries:
      Node: 18.16.1
      npm: 9.5.1
      Yarn: N/A
      pnpm: N/A

Relevant Packages:
      next: 13.4.12
      eslint-config-next: 13.4.12
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 5.1.6

Next.js Config:
      output: N/A

Note: the reported issue relates to the Vercel environments only.

Which area(s) of Next.js are affected? (leave empty if unsure)

App Router

Link to the code that reproduces this issue or a replay of the bug

https://github.com/Windsorborn/next-revalidation-test-app

To Reproduce

1. Clone the provided repository (https://github.com/Windsorborn/next-revalidation-test-app)
2. Setup a project on Vercel and deploy the code
3. View the home page and take note of the timestamp
4. Hit the revalidation endpoint - /api/revalidate?tag=timezone&secret=O5mc4yJp8d6j
5. Refresh the page

Describe the Bug

On first view of the page after hitting the revalidation endpoint, the page requires two refreshes to see the fresh data. This is not consistent with the behaviour of the Pages configuration which only requires one refresh or visit.

See video: https://imgur.com/T4xduRU

Expected Behavior

The expected behaviour is to replicate the res.revalidate function within the Pages configuration where one refresh shows the fresh data.

To reproduce this:

1. Clone the following repository - https://github.com/Windsorborn/next-revalidation-test-pages
2. Setup a project on Vercel and deploy the code
3. View the home page and take note of the timestamp
4. Hit the revalidation endpoint - /api/revalidate?secret=O5mc4yJp8d6j
5. Refresh the page or soft-navigate from Another Page (/another-page)

The timestamp reflects the updated data

See video: https://imgur.com/NqxN44T

Which browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

Vercel

[github-actions]

This closed issue has been automatically locked because it had no new activity for 2 weeks. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.